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cifs: always do is_path_accessible check in cifs_mount
[linux-2.6/linux-acpi-2.6/ibm-acpi-2.6.git] / fs / btrfs / extent-tree.c
blobf619c3cb13b7006cc7f95e273996917bbcebcf67
1 /*
2 * Copyright (C) 2007 Oracle. All rights reserved.
3 *
4 * This program is free software; you can redistribute it and/or
5 * modify it under the terms of the GNU General Public
6 * License v2 as published by the Free Software Foundation.
7 *
8 * This program is distributed in the hope that it will be useful,
9 * but WITHOUT ANY WARRANTY; without even the implied warranty of
10 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
11 * General Public License for more details.
12 *
13 * You should have received a copy of the GNU General Public
14 * License along with this program; if not, write to the
15 * Free Software Foundation, Inc., 59 Temple Place - Suite 330,
16 * Boston, MA 021110-1307, USA.
17 */
18 #include <linux/sched.h>
19 #include <linux/pagemap.h>
20 #include <linux/writeback.h>
21 #include <linux/blkdev.h>
22 #include <linux/sort.h>
23 #include <linux/rcupdate.h>
24 #include <linux/kthread.h>
25 #include <linux/slab.h>
26 #include "compat.h"
27 #include "hash.h"
28 #include "ctree.h"
29 #include "disk-io.h"
30 #include "print-tree.h"
31 #include "transaction.h"
32 #include "volumes.h"
33 #include "locking.h"
34 #include "free-space-cache.h"
35
36 static int update_block_group(struct btrfs_trans_handle *trans,
37 struct btrfs_root *root,
38 u64 bytenr, u64 num_bytes, int alloc);
39 static int __btrfs_free_extent(struct btrfs_trans_handle *trans,
40 struct btrfs_root *root,
41 u64 bytenr, u64 num_bytes, u64 parent,
42 u64 root_objectid, u64 owner_objectid,
43 u64 owner_offset, int refs_to_drop,
44 struct btrfs_delayed_extent_op *extra_op);
45 static void __run_delayed_extent_op(struct btrfs_delayed_extent_op *extent_op,
46 struct extent_buffer *leaf,
47 struct btrfs_extent_item *ei);
48 static int alloc_reserved_file_extent(struct btrfs_trans_handle *trans,
49 struct btrfs_root *root,
50 u64 parent, u64 root_objectid,
51 u64 flags, u64 owner, u64 offset,
52 struct btrfs_key *ins, int ref_mod);
53 static int alloc_reserved_tree_block(struct btrfs_trans_handle *trans,
54 struct btrfs_root *root,
55 u64 parent, u64 root_objectid,
56 u64 flags, struct btrfs_disk_key *key,
57 int level, struct btrfs_key *ins);
58 static int do_chunk_alloc(struct btrfs_trans_handle *trans,
59 struct btrfs_root *extent_root, u64 alloc_bytes,
60 u64 flags, int force);
61 static int find_next_key(struct btrfs_path *path, int level,
62 struct btrfs_key *key);
63 static void dump_space_info(struct btrfs_space_info *info, u64 bytes,
64 int dump_block_groups);
65
66 static noinline int
67 block_group_cache_done(struct btrfs_block_group_cache *cache)
68 {
69 smp_mb();
70 return cache->cached == BTRFS_CACHE_FINISHED;
71 }
72
73 static int block_group_bits(struct btrfs_block_group_cache *cache, u64 bits)
74 {
75 return (cache->flags & bits) == bits;
76 }
77
78 void btrfs_get_block_group(struct btrfs_block_group_cache *cache)
79 {
80 atomic_inc(&cache->count);
81 }
82
83 void btrfs_put_block_group(struct btrfs_block_group_cache *cache)
84 {
85 if (atomic_dec_and_test(&cache->count)) {
86 WARN_ON(cache->pinned > 0);
87 WARN_ON(cache->reserved > 0);
88 WARN_ON(cache->reserved_pinned > 0);
89 kfree(cache);
90 }
91 }
92
93 /*
94 * this adds the block group to the fs_info rb tree for the block group
95 * cache
96 */
97 static int btrfs_add_block_group_cache(struct btrfs_fs_info *info,
98 struct btrfs_block_group_cache *block_group)
99 {
100 struct rb_node **p;
101 struct rb_node *parent = NULL;
102 struct btrfs_block_group_cache *cache;
103
104 spin_lock(&info->block_group_cache_lock);
105 p = &info->block_group_cache_tree.rb_node;
106
107 while (*p) {
108 parent = *p;
109 cache = rb_entry(parent, struct btrfs_block_group_cache,
110 cache_node);
111 if (block_group->key.objectid < cache->key.objectid) {
112 p = &(*p)->rb_left;
113 } else if (block_group->key.objectid > cache->key.objectid) {
114 p = &(*p)->rb_right;
115 } else {
116 spin_unlock(&info->block_group_cache_lock);
117 return -EEXIST;
118 }
119 }
120
121 rb_link_node(&block_group->cache_node, parent, p);
122 rb_insert_color(&block_group->cache_node,
123 &info->block_group_cache_tree);
124 spin_unlock(&info->block_group_cache_lock);
125
126 return 0;
127 }
128
129 /*
130 * This will return the block group at or after bytenr if contains is 0, else
131 * it will return the block group that contains the bytenr
132 */
133 static struct btrfs_block_group_cache *
134 block_group_cache_tree_search(struct btrfs_fs_info *info, u64 bytenr,
135 int contains)
136 {
137 struct btrfs_block_group_cache *cache, *ret = NULL;
138 struct rb_node *n;
139 u64 end, start;
140
141 spin_lock(&info->block_group_cache_lock);
142 n = info->block_group_cache_tree.rb_node;
143
144 while (n) {
145 cache = rb_entry(n, struct btrfs_block_group_cache,
146 cache_node);
147 end = cache->key.objectid + cache->key.offset - 1;
148 start = cache->key.objectid;
149
150 if (bytenr < start) {
151 if (!contains && (!ret || start < ret->key.objectid))
152 ret = cache;
153 n = n->rb_left;
154 } else if (bytenr > start) {
155 if (contains && bytenr <= end) {
156 ret = cache;
157 break;
158 }
159 n = n->rb_right;
160 } else {
161 ret = cache;
162 break;
163 }
164 }
165 if (ret)
166 btrfs_get_block_group(ret);
167 spin_unlock(&info->block_group_cache_lock);
168
169 return ret;
170 }
171
172 static int add_excluded_extent(struct btrfs_root *root,
173 u64 start, u64 num_bytes)
174 {
175 u64 end = start + num_bytes - 1;
176 set_extent_bits(&root->fs_info->freed_extents[0],
177 start, end, EXTENT_UPTODATE, GFP_NOFS);
178 set_extent_bits(&root->fs_info->freed_extents[1],
179 start, end, EXTENT_UPTODATE, GFP_NOFS);
180 return 0;
181 }
182
183 static void free_excluded_extents(struct btrfs_root *root,
184 struct btrfs_block_group_cache *cache)
185 {
186 u64 start, end;
187
188 start = cache->key.objectid;
189 end = start + cache->key.offset - 1;
190
191 clear_extent_bits(&root->fs_info->freed_extents[0],
192 start, end, EXTENT_UPTODATE, GFP_NOFS);
193 clear_extent_bits(&root->fs_info->freed_extents[1],
194 start, end, EXTENT_UPTODATE, GFP_NOFS);
195 }
196
197 static int exclude_super_stripes(struct btrfs_root *root,
198 struct btrfs_block_group_cache *cache)
199 {
200 u64 bytenr;
201 u64 *logical;
202 int stripe_len;
203 int i, nr, ret;
204
205 if (cache->key.objectid < BTRFS_SUPER_INFO_OFFSET) {
206 stripe_len = BTRFS_SUPER_INFO_OFFSET - cache->key.objectid;
207 cache->bytes_super += stripe_len;
208 ret = add_excluded_extent(root, cache->key.objectid,
209 stripe_len);
210 BUG_ON(ret);
211 }
212
213 for (i = 0; i < BTRFS_SUPER_MIRROR_MAX; i++) {
214 bytenr = btrfs_sb_offset(i);
215 ret = btrfs_rmap_block(&root->fs_info->mapping_tree,
216 cache->key.objectid, bytenr,
217 0, &logical, &nr, &stripe_len);
218 BUG_ON(ret);
219
220 while (nr--) {
221 cache->bytes_super += stripe_len;
222 ret = add_excluded_extent(root, logical[nr],
223 stripe_len);
224 BUG_ON(ret);
225 }
226
227 kfree(logical);
228 }
229 return 0;
230 }
231
232 static struct btrfs_caching_control *
233 get_caching_control(struct btrfs_block_group_cache *cache)
234 {
235 struct btrfs_caching_control *ctl;
236
237 spin_lock(&cache->lock);
238 if (cache->cached != BTRFS_CACHE_STARTED) {
239 spin_unlock(&cache->lock);
240 return NULL;
241 }
242
243 /* We're loading it the fast way, so we don't have a caching_ctl. */
244 if (!cache->caching_ctl) {
245 spin_unlock(&cache->lock);
246 return NULL;
247 }
248
249 ctl = cache->caching_ctl;
250 atomic_inc(&ctl->count);
251 spin_unlock(&cache->lock);
252 return ctl;
253 }
254
255 static void put_caching_control(struct btrfs_caching_control *ctl)
256 {
257 if (atomic_dec_and_test(&ctl->count))
258 kfree(ctl);
259 }
260
261 /*
262 * this is only called by cache_block_group, since we could have freed extents
263 * we need to check the pinned_extents for any extents that can't be used yet
264 * since their free space will be released as soon as the transaction commits.
265 */
266 static u64 add_new_free_space(struct btrfs_block_group_cache *block_group,
267 struct btrfs_fs_info *info, u64 start, u64 end)
268 {
269 u64 extent_start, extent_end, size, total_added = 0;
270 int ret;
271
272 while (start < end) {
273 ret = find_first_extent_bit(info->pinned_extents, start,
274 &extent_start, &extent_end,
275 EXTENT_DIRTY | EXTENT_UPTODATE);
276 if (ret)
277 break;
278
279 if (extent_start <= start) {
280 start = extent_end + 1;
281 } else if (extent_start > start && extent_start < end) {
282 size = extent_start - start;
283 total_added += size;
284 ret = btrfs_add_free_space(block_group, start,
285 size);
286 BUG_ON(ret);
287 start = extent_end + 1;
288 } else {
289 break;
290 }
291 }
292
293 if (start < end) {
294 size = end - start;
295 total_added += size;
296 ret = btrfs_add_free_space(block_group, start, size);
297 BUG_ON(ret);
298 }
299
300 return total_added;
301 }
302
303 static int caching_kthread(void *data)
304 {
305 struct btrfs_block_group_cache *block_group = data;
306 struct btrfs_fs_info *fs_info = block_group->fs_info;
307 struct btrfs_caching_control *caching_ctl = block_group->caching_ctl;
308 struct btrfs_root *extent_root = fs_info->extent_root;
309 struct btrfs_path *path;
310 struct extent_buffer *leaf;
311 struct btrfs_key key;
312 u64 total_found = 0;
313 u64 last = 0;
314 u32 nritems;
315 int ret = 0;
316
317 path = btrfs_alloc_path();
318 if (!path)
319 return -ENOMEM;
320
321 last = max_t(u64, block_group->key.objectid, BTRFS_SUPER_INFO_OFFSET);
322
323 /*
324 * We don't want to deadlock with somebody trying to allocate a new
325 * extent for the extent root while also trying to search the extent
326 * root to add free space. So we skip locking and search the commit
327 * root, since its read-only
328 */
329 path->skip_locking = 1;
330 path->search_commit_root = 1;
331 path->reada = 2;
332
333 key.objectid = last;
334 key.offset = 0;
335 key.type = BTRFS_EXTENT_ITEM_KEY;
336 again:
337 mutex_lock(&caching_ctl->mutex);
338 /* need to make sure the commit_root doesn't disappear */
339 down_read(&fs_info->extent_commit_sem);
340
341 ret = btrfs_search_slot(NULL, extent_root, &key, path, 0, 0);
342 if (ret < 0)
343 goto err;
344
345 leaf = path->nodes[0];
346 nritems = btrfs_header_nritems(leaf);
347
348 while (1) {
349 smp_mb();
350 if (fs_info->closing > 1) {
351 last = (u64)-1;
352 break;
353 }
354
355 if (path->slots[0] < nritems) {
356 btrfs_item_key_to_cpu(leaf, &key, path->slots[0]);
357 } else {
358 ret = find_next_key(path, 0, &key);
359 if (ret)
360 break;
361
362 caching_ctl->progress = last;
363 btrfs_release_path(extent_root, path);
364 up_read(&fs_info->extent_commit_sem);
365 mutex_unlock(&caching_ctl->mutex);
366 if (btrfs_transaction_in_commit(fs_info))
367 schedule_timeout(1);
368 else
369 cond_resched();
370 goto again;
371 }
372
373 if (key.objectid < block_group->key.objectid) {
374 path->slots[0]++;
375 continue;
376 }
377
378 if (key.objectid >= block_group->key.objectid +
379 block_group->key.offset)
380 break;
381
382 if (key.type == BTRFS_EXTENT_ITEM_KEY) {
383 total_found += add_new_free_space(block_group,
384 fs_info, last,
385 key.objectid);
386 last = key.objectid + key.offset;
387
388 if (total_found > (1024 * 1024 * 2)) {
389 total_found = 0;
390 wake_up(&caching_ctl->wait);
391 }
392 }
393 path->slots[0]++;
394 }
395 ret = 0;
396
397 total_found += add_new_free_space(block_group, fs_info, last,
398 block_group->key.objectid +
399 block_group->key.offset);
400 caching_ctl->progress = (u64)-1;
401
402 spin_lock(&block_group->lock);
403 block_group->caching_ctl = NULL;
404 block_group->cached = BTRFS_CACHE_FINISHED;
405 spin_unlock(&block_group->lock);
406
407 err:
408 btrfs_free_path(path);
409 up_read(&fs_info->extent_commit_sem);
410
411 free_excluded_extents(extent_root, block_group);
412
413 mutex_unlock(&caching_ctl->mutex);
414 wake_up(&caching_ctl->wait);
415
416 put_caching_control(caching_ctl);
417 atomic_dec(&block_group->space_info->caching_threads);
418 btrfs_put_block_group(block_group);
419
420 return 0;
421 }
422
423 static int cache_block_group(struct btrfs_block_group_cache *cache,
424 struct btrfs_trans_handle *trans,
425 struct btrfs_root *root,
426 int load_cache_only)
427 {
428 struct btrfs_fs_info *fs_info = cache->fs_info;
429 struct btrfs_caching_control *caching_ctl;
430 struct task_struct *tsk;
431 int ret = 0;
432
433 smp_mb();
434 if (cache->cached != BTRFS_CACHE_NO)
435 return 0;
436
437 /*
438 * We can't do the read from on-disk cache during a commit since we need
439 * to have the normal tree locking. Also if we are currently trying to
440 * allocate blocks for the tree root we can't do the fast caching since
441 * we likely hold important locks.
442 */
443 if (trans && (!trans->transaction->in_commit) &&
444 (root && root != root->fs_info->tree_root)) {
445 spin_lock(&cache->lock);
446 if (cache->cached != BTRFS_CACHE_NO) {
447 spin_unlock(&cache->lock);
448 return 0;
449 }
450 cache->cached = BTRFS_CACHE_STARTED;
451 spin_unlock(&cache->lock);
452
453 ret = load_free_space_cache(fs_info, cache);
454
455 spin_lock(&cache->lock);
456 if (ret == 1) {
457 cache->cached = BTRFS_CACHE_FINISHED;
458 cache->last_byte_to_unpin = (u64)-1;
459 } else {
460 cache->cached = BTRFS_CACHE_NO;
461 }
462 spin_unlock(&cache->lock);
463 if (ret == 1) {
464 free_excluded_extents(fs_info->extent_root, cache);
465 return 0;
466 }
467 }
468
469 if (load_cache_only)
470 return 0;
471
472 caching_ctl = kzalloc(sizeof(*caching_ctl), GFP_NOFS);
473 BUG_ON(!caching_ctl);
474
475 INIT_LIST_HEAD(&caching_ctl->list);
476 mutex_init(&caching_ctl->mutex);
477 init_waitqueue_head(&caching_ctl->wait);
478 caching_ctl->block_group = cache;
479 caching_ctl->progress = cache->key.objectid;
480 /* one for caching kthread, one for caching block group list */
481 atomic_set(&caching_ctl->count, 2);
482
483 spin_lock(&cache->lock);
484 if (cache->cached != BTRFS_CACHE_NO) {
485 spin_unlock(&cache->lock);
486 kfree(caching_ctl);
487 return 0;
488 }
489 cache->caching_ctl = caching_ctl;
490 cache->cached = BTRFS_CACHE_STARTED;
491 spin_unlock(&cache->lock);
492
493 down_write(&fs_info->extent_commit_sem);
494 list_add_tail(&caching_ctl->list, &fs_info->caching_block_groups);
495 up_write(&fs_info->extent_commit_sem);
496
497 atomic_inc(&cache->space_info->caching_threads);
498 btrfs_get_block_group(cache);
499
500 tsk = kthread_run(caching_kthread, cache, "btrfs-cache-%llu\n",
501 cache->key.objectid);
502 if (IS_ERR(tsk)) {
503 ret = PTR_ERR(tsk);
504 printk(KERN_ERR "error running thread %d\n", ret);
505 BUG();
506 }
507
508 return ret;
509 }
510
511 /*
512 * return the block group that starts at or after bytenr
513 */
514 static struct btrfs_block_group_cache *
515 btrfs_lookup_first_block_group(struct btrfs_fs_info *info, u64 bytenr)
516 {
517 struct btrfs_block_group_cache *cache;
518
519 cache = block_group_cache_tree_search(info, bytenr, 0);
520
521 return cache;
522 }
523
524 /*
525 * return the block group that contains the given bytenr
526 */
527 struct btrfs_block_group_cache *btrfs_lookup_block_group(
528 struct btrfs_fs_info *info,
529 u64 bytenr)
530 {
531 struct btrfs_block_group_cache *cache;
532
533 cache = block_group_cache_tree_search(info, bytenr, 1);
534
535 return cache;
536 }
537
538 static struct btrfs_space_info *__find_space_info(struct btrfs_fs_info *info,
539 u64 flags)
540 {
541 struct list_head *head = &info->space_info;
542 struct btrfs_space_info *found;
543
544 flags &= BTRFS_BLOCK_GROUP_DATA | BTRFS_BLOCK_GROUP_SYSTEM |
545 BTRFS_BLOCK_GROUP_METADATA;
546
547 rcu_read_lock();
548 list_for_each_entry_rcu(found, head, list) {
549 if (found->flags & flags) {
550 rcu_read_unlock();
551 return found;
552 }
553 }
554 rcu_read_unlock();
555 return NULL;
556 }
557
558 /*
559 * after adding space to the filesystem, we need to clear the full flags
560 * on all the space infos.
561 */
562 void btrfs_clear_space_info_full(struct btrfs_fs_info *info)
563 {
564 struct list_head *head = &info->space_info;
565 struct btrfs_space_info *found;
566
567 rcu_read_lock();
568 list_for_each_entry_rcu(found, head, list)
569 found->full = 0;
570 rcu_read_unlock();
571 }
572
573 static u64 div_factor(u64 num, int factor)
574 {
575 if (factor == 10)
576 return num;
577 num *= factor;
578 do_div(num, 10);
579 return num;
580 }
581
582 static u64 div_factor_fine(u64 num, int factor)
583 {
584 if (factor == 100)
585 return num;
586 num *= factor;
587 do_div(num, 100);
588 return num;
589 }
590
591 u64 btrfs_find_block_group(struct btrfs_root *root,
592 u64 search_start, u64 search_hint, int owner)
593 {
594 struct btrfs_block_group_cache *cache;
595 u64 used;
596 u64 last = max(search_hint, search_start);
597 u64 group_start = 0;
598 int full_search = 0;
599 int factor = 9;
600 int wrapped = 0;
601 again:
602 while (1) {
603 cache = btrfs_lookup_first_block_group(root->fs_info, last);
604 if (!cache)
605 break;
606
607 spin_lock(&cache->lock);
608 last = cache->key.objectid + cache->key.offset;
609 used = btrfs_block_group_used(&cache->item);
610
611 if ((full_search || !cache->ro) &&
612 block_group_bits(cache, BTRFS_BLOCK_GROUP_METADATA)) {
613 if (used + cache->pinned + cache->reserved <
614 div_factor(cache->key.offset, factor)) {
615 group_start = cache->key.objectid;
616 spin_unlock(&cache->lock);
617 btrfs_put_block_group(cache);
618 goto found;
619 }
620 }
621 spin_unlock(&cache->lock);
622 btrfs_put_block_group(cache);
623 cond_resched();
624 }
625 if (!wrapped) {
626 last = search_start;
627 wrapped = 1;
628 goto again;
629 }
630 if (!full_search && factor < 10) {
631 last = search_start;
632 full_search = 1;
633 factor = 10;
634 goto again;
635 }
636 found:
637 return group_start;
638 }
639
640 /* simple helper to search for an existing extent at a given offset */
641 int btrfs_lookup_extent(struct btrfs_root *root, u64 start, u64 len)
642 {
643 int ret;
644 struct btrfs_key key;
645 struct btrfs_path *path;
646
647 path = btrfs_alloc_path();
648 BUG_ON(!path);
649 key.objectid = start;
650 key.offset = len;
651 btrfs_set_key_type(&key, BTRFS_EXTENT_ITEM_KEY);
652 ret = btrfs_search_slot(NULL, root->fs_info->extent_root, &key, path,
653 0, 0);
654 btrfs_free_path(path);
655 return ret;
656 }
657
658 /*
659 * helper function to lookup reference count and flags of extent.
660 *
661 * the head node for delayed ref is used to store the sum of all the
662 * reference count modifications queued up in the rbtree. the head
663 * node may also store the extent flags to set. This way you can check
664 * to see what the reference count and extent flags would be if all of
665 * the delayed refs are not processed.
666 */
667 int btrfs_lookup_extent_info(struct btrfs_trans_handle *trans,
668 struct btrfs_root *root, u64 bytenr,
669 u64 num_bytes, u64 *refs, u64 *flags)
670 {
671 struct btrfs_delayed_ref_head *head;
672 struct btrfs_delayed_ref_root *delayed_refs;
673 struct btrfs_path *path;
674 struct btrfs_extent_item *ei;
675 struct extent_buffer *leaf;
676 struct btrfs_key key;
677 u32 item_size;
678 u64 num_refs;
679 u64 extent_flags;
680 int ret;
681
682 path = btrfs_alloc_path();
683 if (!path)
684 return -ENOMEM;
685
686 key.objectid = bytenr;
687 key.type = BTRFS_EXTENT_ITEM_KEY;
688 key.offset = num_bytes;
689 if (!trans) {
690 path->skip_locking = 1;
691 path->search_commit_root = 1;
692 }
693 again:
694 ret = btrfs_search_slot(trans, root->fs_info->extent_root,
695 &key, path, 0, 0);
696 if (ret < 0)
697 goto out_free;
698
699 if (ret == 0) {
700 leaf = path->nodes[0];
701 item_size = btrfs_item_size_nr(leaf, path->slots[0]);
702 if (item_size >= sizeof(*ei)) {
703 ei = btrfs_item_ptr(leaf, path->slots[0],
704 struct btrfs_extent_item);
705 num_refs = btrfs_extent_refs(leaf, ei);
706 extent_flags = btrfs_extent_flags(leaf, ei);
707 } else {
708 #ifdef BTRFS_COMPAT_EXTENT_TREE_V0
709 struct btrfs_extent_item_v0 *ei0;
710 BUG_ON(item_size != sizeof(*ei0));
711 ei0 = btrfs_item_ptr(leaf, path->slots[0],
712 struct btrfs_extent_item_v0);
713 num_refs = btrfs_extent_refs_v0(leaf, ei0);
714 /* FIXME: this isn't correct for data */
715 extent_flags = BTRFS_BLOCK_FLAG_FULL_BACKREF;
716 #else
717 BUG();
718 #endif
719 }
720 BUG_ON(num_refs == 0);
721 } else {
722 num_refs = 0;
723 extent_flags = 0;
724 ret = 0;
725 }
726
727 if (!trans)
728 goto out;
729
730 delayed_refs = &trans->transaction->delayed_refs;
731 spin_lock(&delayed_refs->lock);
732 head = btrfs_find_delayed_ref_head(trans, bytenr);
733 if (head) {
734 if (!mutex_trylock(&head->mutex)) {
735 atomic_inc(&head->node.refs);
736 spin_unlock(&delayed_refs->lock);
737
738 btrfs_release_path(root->fs_info->extent_root, path);
739
740 mutex_lock(&head->mutex);
741 mutex_unlock(&head->mutex);
742 btrfs_put_delayed_ref(&head->node);
743 goto again;
744 }
745 if (head->extent_op && head->extent_op->update_flags)
746 extent_flags |= head->extent_op->flags_to_set;
747 else
748 BUG_ON(num_refs == 0);
749
750 num_refs += head->node.ref_mod;
751 mutex_unlock(&head->mutex);
752 }
753 spin_unlock(&delayed_refs->lock);
754 out:
755 WARN_ON(num_refs == 0);
756 if (refs)
757 *refs = num_refs;
758 if (flags)
759 *flags = extent_flags;
760 out_free:
761 btrfs_free_path(path);
762 return ret;
763 }
764
765 /*
766 * Back reference rules. Back refs have three main goals:
767 *
768 * 1) differentiate between all holders of references to an extent so that
769 * when a reference is dropped we can make sure it was a valid reference
770 * before freeing the extent.
771 *
772 * 2) Provide enough information to quickly find the holders of an extent
773 * if we notice a given block is corrupted or bad.
774 *
775 * 3) Make it easy to migrate blocks for FS shrinking or storage pool
776 * maintenance. This is actually the same as #2, but with a slightly
777 * different use case.
778 *
779 * There are two kinds of back refs. The implicit back refs is optimized
780 * for pointers in non-shared tree blocks. For a given pointer in a block,
781 * back refs of this kind provide information about the block's owner tree
782 * and the pointer's key. These information allow us to find the block by
783 * b-tree searching. The full back refs is for pointers in tree blocks not
784 * referenced by their owner trees. The location of tree block is recorded
785 * in the back refs. Actually the full back refs is generic, and can be
786 * used in all cases the implicit back refs is used. The major shortcoming
787 * of the full back refs is its overhead. Every time a tree block gets
788 * COWed, we have to update back refs entry for all pointers in it.
789 *
790 * For a newly allocated tree block, we use implicit back refs for
791 * pointers in it. This means most tree related operations only involve
792 * implicit back refs. For a tree block created in old transaction, the
793 * only way to drop a reference to it is COW it. So we can detect the
794 * event that tree block loses its owner tree's reference and do the
795 * back refs conversion.
796 *
797 * When a tree block is COW'd through a tree, there are four cases:
798 *
799 * The reference count of the block is one and the tree is the block's
800 * owner tree. Nothing to do in this case.
801 *
802 * The reference count of the block is one and the tree is not the
803 * block's owner tree. In this case, full back refs is used for pointers
804 * in the block. Remove these full back refs, add implicit back refs for
805 * every pointers in the new block.
806 *
807 * The reference count of the block is greater than one and the tree is
808 * the block's owner tree. In this case, implicit back refs is used for
809 * pointers in the block. Add full back refs for every pointers in the
810 * block, increase lower level extents' reference counts. The original
811 * implicit back refs are entailed to the new block.
812 *
813 * The reference count of the block is greater than one and the tree is
814 * not the block's owner tree. Add implicit back refs for every pointer in
815 * the new block, increase lower level extents' reference count.
816 *
817 * Back Reference Key composing:
818 *
819 * The key objectid corresponds to the first byte in the extent,
820 * The key type is used to differentiate between types of back refs.
821 * There are different meanings of the key offset for different types
822 * of back refs.
823 *
824 * File extents can be referenced by:
825 *
826 * - multiple snapshots, subvolumes, or different generations in one subvol
827 * - different files inside a single subvolume
828 * - different offsets inside a file (bookend extents in file.c)
829 *
830 * The extent ref structure for the implicit back refs has fields for:
831 *
832 * - Objectid of the subvolume root
833 * - objectid of the file holding the reference
834 * - original offset in the file
835 * - how many bookend extents
836 *
837 * The key offset for the implicit back refs is hash of the first
838 * three fields.
839 *
840 * The extent ref structure for the full back refs has field for:
841 *
842 * - number of pointers in the tree leaf
843 *
844 * The key offset for the implicit back refs is the first byte of
845 * the tree leaf
846 *
847 * When a file extent is allocated, The implicit back refs is used.
848 * the fields are filled in:
849 *
850 * (root_key.objectid, inode objectid, offset in file, 1)
851 *
852 * When a file extent is removed file truncation, we find the
853 * corresponding implicit back refs and check the following fields:
854 *
855 * (btrfs_header_owner(leaf), inode objectid, offset in file)
856 *
857 * Btree extents can be referenced by:
858 *
859 * - Different subvolumes
860 *
861 * Both the implicit back refs and the full back refs for tree blocks
862 * only consist of key. The key offset for the implicit back refs is
863 * objectid of block's owner tree. The key offset for the full back refs
864 * is the first byte of parent block.
865 *
866 * When implicit back refs is used, information about the lowest key and
867 * level of the tree block are required. These information are stored in
868 * tree block info structure.
869 */
870
871 #ifdef BTRFS_COMPAT_EXTENT_TREE_V0
872 static int convert_extent_item_v0(struct btrfs_trans_handle *trans,
873 struct btrfs_root *root,
874 struct btrfs_path *path,
875 u64 owner, u32 extra_size)
876 {
877 struct btrfs_extent_item *item;
878 struct btrfs_extent_item_v0 *ei0;
879 struct btrfs_extent_ref_v0 *ref0;
880 struct btrfs_tree_block_info *bi;
881 struct extent_buffer *leaf;
882 struct btrfs_key key;
883 struct btrfs_key found_key;
884 u32 new_size = sizeof(*item);
885 u64 refs;
886 int ret;
887
888 leaf = path->nodes[0];
889 BUG_ON(btrfs_item_size_nr(leaf, path->slots[0]) != sizeof(*ei0));
890
891 btrfs_item_key_to_cpu(leaf, &key, path->slots[0]);
892 ei0 = btrfs_item_ptr(leaf, path->slots[0],
893 struct btrfs_extent_item_v0);
894 refs = btrfs_extent_refs_v0(leaf, ei0);
895
896 if (owner == (u64)-1) {
897 while (1) {
898 if (path->slots[0] >= btrfs_header_nritems(leaf)) {
899 ret = btrfs_next_leaf(root, path);
900 if (ret < 0)
901 return ret;
902 BUG_ON(ret > 0);
903 leaf = path->nodes[0];
904 }
905 btrfs_item_key_to_cpu(leaf, &found_key,
906 path->slots[0]);
907 BUG_ON(key.objectid != found_key.objectid);
908 if (found_key.type != BTRFS_EXTENT_REF_V0_KEY) {
909 path->slots[0]++;
910 continue;
911 }
912 ref0 = btrfs_item_ptr(leaf, path->slots[0],
913 struct btrfs_extent_ref_v0);
914 owner = btrfs_ref_objectid_v0(leaf, ref0);
915 break;
916 }
917 }
918 btrfs_release_path(root, path);
919
920 if (owner < BTRFS_FIRST_FREE_OBJECTID)
921 new_size += sizeof(*bi);
922
923 new_size -= sizeof(*ei0);
924 ret = btrfs_search_slot(trans, root, &key, path,
925 new_size + extra_size, 1);
926 if (ret < 0)
927 return ret;
928 BUG_ON(ret);
929
930 ret = btrfs_extend_item(trans, root, path, new_size);
931 BUG_ON(ret);
932
933 leaf = path->nodes[0];
934 item = btrfs_item_ptr(leaf, path->slots[0], struct btrfs_extent_item);
935 btrfs_set_extent_refs(leaf, item, refs);
936 /* FIXME: get real generation */
937 btrfs_set_extent_generation(leaf, item, 0);
938 if (owner < BTRFS_FIRST_FREE_OBJECTID) {
939 btrfs_set_extent_flags(leaf, item,
940 BTRFS_EXTENT_FLAG_TREE_BLOCK |
941 BTRFS_BLOCK_FLAG_FULL_BACKREF);
942 bi = (struct btrfs_tree_block_info *)(item + 1);
943 /* FIXME: get first key of the block */
944 memset_extent_buffer(leaf, 0, (unsigned long)bi, sizeof(*bi));
945 btrfs_set_tree_block_level(leaf, bi, (int)owner);
946 } else {
947 btrfs_set_extent_flags(leaf, item, BTRFS_EXTENT_FLAG_DATA);
948 }
949 btrfs_mark_buffer_dirty(leaf);
950 return 0;
951 }
952 #endif
953
954 static u64 hash_extent_data_ref(u64 root_objectid, u64 owner, u64 offset)
955 {
956 u32 high_crc = ~(u32)0;
957 u32 low_crc = ~(u32)0;
958 __le64 lenum;
959
960 lenum = cpu_to_le64(root_objectid);
961 high_crc = crc32c(high_crc, &lenum, sizeof(lenum));
962 lenum = cpu_to_le64(owner);
963 low_crc = crc32c(low_crc, &lenum, sizeof(lenum));
964 lenum = cpu_to_le64(offset);
965 low_crc = crc32c(low_crc, &lenum, sizeof(lenum));
966
967 return ((u64)high_crc << 31) ^ (u64)low_crc;
968 }
969
970 static u64 hash_extent_data_ref_item(struct extent_buffer *leaf,
971 struct btrfs_extent_data_ref *ref)
972 {
973 return hash_extent_data_ref(btrfs_extent_data_ref_root(leaf, ref),
974 btrfs_extent_data_ref_objectid(leaf, ref),
975 btrfs_extent_data_ref_offset(leaf, ref));
976 }
977
978 static int match_extent_data_ref(struct extent_buffer *leaf,
979 struct btrfs_extent_data_ref *ref,
980 u64 root_objectid, u64 owner, u64 offset)
981 {
982 if (btrfs_extent_data_ref_root(leaf, ref) != root_objectid ||
983 btrfs_extent_data_ref_objectid(leaf, ref) != owner ||
984 btrfs_extent_data_ref_offset(leaf, ref) != offset)
985 return 0;
986 return 1;
987 }
988
989 static noinline int lookup_extent_data_ref(struct btrfs_trans_handle *trans,
990 struct btrfs_root *root,
991 struct btrfs_path *path,
992 u64 bytenr, u64 parent,
993 u64 root_objectid,
994 u64 owner, u64 offset)
995 {
996 struct btrfs_key key;
997 struct btrfs_extent_data_ref *ref;
998 struct extent_buffer *leaf;
999 u32 nritems;
1000 int ret;
1001 int recow;
1002 int err = -ENOENT;
1003
1004 key.objectid = bytenr;
1005 if (parent) {
1006 key.type = BTRFS_SHARED_DATA_REF_KEY;
1007 key.offset = parent;
1008 } else {
1009 key.type = BTRFS_EXTENT_DATA_REF_KEY;
1010 key.offset = hash_extent_data_ref(root_objectid,
1011 owner, offset);
1012 }
1013 again:
1014 recow = 0;
1015 ret = btrfs_search_slot(trans, root, &key, path, -1, 1);
1016 if (ret < 0) {
1017 err = ret;
1018 goto fail;
1019 }
1020
1021 if (parent) {
1022 if (!ret)
1023 return 0;
1024 #ifdef BTRFS_COMPAT_EXTENT_TREE_V0
1025 key.type = BTRFS_EXTENT_REF_V0_KEY;
1026 btrfs_release_path(root, path);
1027 ret = btrfs_search_slot(trans, root, &key, path, -1, 1);
1028 if (ret < 0) {
1029 err = ret;
1030 goto fail;
1031 }
1032 if (!ret)
1033 return 0;
1034 #endif
1035 goto fail;
1036 }
1037
1038 leaf = path->nodes[0];
1039 nritems = btrfs_header_nritems(leaf);
1040 while (1) {
1041 if (path->slots[0] >= nritems) {
1042 ret = btrfs_next_leaf(root, path);
1043 if (ret < 0)
1044 err = ret;
1045 if (ret)
1046 goto fail;
1047
1048 leaf = path->nodes[0];
1049 nritems = btrfs_header_nritems(leaf);
1050 recow = 1;
1051 }
1052
1053 btrfs_item_key_to_cpu(leaf, &key, path->slots[0]);
1054 if (key.objectid != bytenr ||
1055 key.type != BTRFS_EXTENT_DATA_REF_KEY)
1056 goto fail;
1057
1058 ref = btrfs_item_ptr(leaf, path->slots[0],
1059 struct btrfs_extent_data_ref);
1060
1061 if (match_extent_data_ref(leaf, ref, root_objectid,
1062 owner, offset)) {
1063 if (recow) {
1064 btrfs_release_path(root, path);
1065 goto again;
1066 }
1067 err = 0;
1068 break;
1069 }
1070 path->slots[0]++;
1071 }
1072 fail:
1073 return err;
1074 }
1075
1076 static noinline int insert_extent_data_ref(struct btrfs_trans_handle *trans,
1077 struct btrfs_root *root,
1078 struct btrfs_path *path,
1079 u64 bytenr, u64 parent,
1080 u64 root_objectid, u64 owner,
1081 u64 offset, int refs_to_add)
1082 {
1083 struct btrfs_key key;
1084 struct extent_buffer *leaf;
1085 u32 size;
1086 u32 num_refs;
1087 int ret;
1088
1089 key.objectid = bytenr;
1090 if (parent) {
1091 key.type = BTRFS_SHARED_DATA_REF_KEY;
1092 key.offset = parent;
1093 size = sizeof(struct btrfs_shared_data_ref);
1094 } else {
1095 key.type = BTRFS_EXTENT_DATA_REF_KEY;
1096 key.offset = hash_extent_data_ref(root_objectid,
1097 owner, offset);
1098 size = sizeof(struct btrfs_extent_data_ref);
1099 }
1100
1101 ret = btrfs_insert_empty_item(trans, root, path, &key, size);
1102 if (ret && ret != -EEXIST)
1103 goto fail;
1104
1105 leaf = path->nodes[0];
1106 if (parent) {
1107 struct btrfs_shared_data_ref *ref;
1108 ref = btrfs_item_ptr(leaf, path->slots[0],
1109 struct btrfs_shared_data_ref);
1110 if (ret == 0) {
1111 btrfs_set_shared_data_ref_count(leaf, ref, refs_to_add);
1112 } else {
1113 num_refs = btrfs_shared_data_ref_count(leaf, ref);
1114 num_refs += refs_to_add;
1115 btrfs_set_shared_data_ref_count(leaf, ref, num_refs);
1116 }
1117 } else {
1118 struct btrfs_extent_data_ref *ref;
1119 while (ret == -EEXIST) {
1120 ref = btrfs_item_ptr(leaf, path->slots[0],
1121 struct btrfs_extent_data_ref);
1122 if (match_extent_data_ref(leaf, ref, root_objectid,
1123 owner, offset))
1124 break;
1125 btrfs_release_path(root, path);
1126 key.offset++;
1127 ret = btrfs_insert_empty_item(trans, root, path, &key,
1128 size);
1129 if (ret && ret != -EEXIST)
1130 goto fail;
1131
1132 leaf = path->nodes[0];
1133 }
1134 ref = btrfs_item_ptr(leaf, path->slots[0],
1135 struct btrfs_extent_data_ref);
1136 if (ret == 0) {
1137 btrfs_set_extent_data_ref_root(leaf, ref,
1138 root_objectid);
1139 btrfs_set_extent_data_ref_objectid(leaf, ref, owner);
1140 btrfs_set_extent_data_ref_offset(leaf, ref, offset);
1141 btrfs_set_extent_data_ref_count(leaf, ref, refs_to_add);
1142 } else {
1143 num_refs = btrfs_extent_data_ref_count(leaf, ref);
1144 num_refs += refs_to_add;
1145 btrfs_set_extent_data_ref_count(leaf, ref, num_refs);
1146 }
1147 }
1148 btrfs_mark_buffer_dirty(leaf);
1149 ret = 0;
1150 fail:
1151 btrfs_release_path(root, path);
1152 return ret;
1153 }
1154
1155 static noinline int remove_extent_data_ref(struct btrfs_trans_handle *trans,
1156 struct btrfs_root *root,
1157 struct btrfs_path *path,
1158 int refs_to_drop)
1159 {
1160 struct btrfs_key key;
1161 struct btrfs_extent_data_ref *ref1 = NULL;
1162 struct btrfs_shared_data_ref *ref2 = NULL;
1163 struct extent_buffer *leaf;
1164 u32 num_refs = 0;
1165 int ret = 0;
1166
1167 leaf = path->nodes[0];
1168 btrfs_item_key_to_cpu(leaf, &key, path->slots[0]);
1169
1170 if (key.type == BTRFS_EXTENT_DATA_REF_KEY) {
1171 ref1 = btrfs_item_ptr(leaf, path->slots[0],
1172 struct btrfs_extent_data_ref);
1173 num_refs = btrfs_extent_data_ref_count(leaf, ref1);
1174 } else if (key.type == BTRFS_SHARED_DATA_REF_KEY) {
1175 ref2 = btrfs_item_ptr(leaf, path->slots[0],
1176 struct btrfs_shared_data_ref);
1177 num_refs = btrfs_shared_data_ref_count(leaf, ref2);
1178 #ifdef BTRFS_COMPAT_EXTENT_TREE_V0
1179 } else if (key.type == BTRFS_EXTENT_REF_V0_KEY) {
1180 struct btrfs_extent_ref_v0 *ref0;
1181 ref0 = btrfs_item_ptr(leaf, path->slots[0],
1182 struct btrfs_extent_ref_v0);
1183 num_refs = btrfs_ref_count_v0(leaf, ref0);
1184 #endif
1185 } else {
1186 BUG();
1187 }
1188
1189 BUG_ON(num_refs < refs_to_drop);
1190 num_refs -= refs_to_drop;
1191
1192 if (num_refs == 0) {
1193 ret = btrfs_del_item(trans, root, path);
1194 } else {
1195 if (key.type == BTRFS_EXTENT_DATA_REF_KEY)
1196 btrfs_set_extent_data_ref_count(leaf, ref1, num_refs);
1197 else if (key.type == BTRFS_SHARED_DATA_REF_KEY)
1198 btrfs_set_shared_data_ref_count(leaf, ref2, num_refs);
1199 #ifdef BTRFS_COMPAT_EXTENT_TREE_V0
1200 else {
1201 struct btrfs_extent_ref_v0 *ref0;
1202 ref0 = btrfs_item_ptr(leaf, path->slots[0],
1203 struct btrfs_extent_ref_v0);
1204 btrfs_set_ref_count_v0(leaf, ref0, num_refs);
1205 }
1206 #endif
1207 btrfs_mark_buffer_dirty(leaf);
1208 }
1209 return ret;
1210 }
1211
1212 static noinline u32 extent_data_ref_count(struct btrfs_root *root,
1213 struct btrfs_path *path,
1214 struct btrfs_extent_inline_ref *iref)
1215 {
1216 struct btrfs_key key;
1217 struct extent_buffer *leaf;
1218 struct btrfs_extent_data_ref *ref1;
1219 struct btrfs_shared_data_ref *ref2;
1220 u32 num_refs = 0;
1221
1222 leaf = path->nodes[0];
1223 btrfs_item_key_to_cpu(leaf, &key, path->slots[0]);
1224 if (iref) {
1225 if (btrfs_extent_inline_ref_type(leaf, iref) ==
1226 BTRFS_EXTENT_DATA_REF_KEY) {
1227 ref1 = (struct btrfs_extent_data_ref *)(&iref->offset);
1228 num_refs = btrfs_extent_data_ref_count(leaf, ref1);
1229 } else {
1230 ref2 = (struct btrfs_shared_data_ref *)(iref + 1);
1231 num_refs = btrfs_shared_data_ref_count(leaf, ref2);
1232 }
1233 } else if (key.type == BTRFS_EXTENT_DATA_REF_KEY) {
1234 ref1 = btrfs_item_ptr(leaf, path->slots[0],
1235 struct btrfs_extent_data_ref);
1236 num_refs = btrfs_extent_data_ref_count(leaf, ref1);
1237 } else if (key.type == BTRFS_SHARED_DATA_REF_KEY) {
1238 ref2 = btrfs_item_ptr(leaf, path->slots[0],
1239 struct btrfs_shared_data_ref);
1240 num_refs = btrfs_shared_data_ref_count(leaf, ref2);
1241 #ifdef BTRFS_COMPAT_EXTENT_TREE_V0
1242 } else if (key.type == BTRFS_EXTENT_REF_V0_KEY) {
1243 struct btrfs_extent_ref_v0 *ref0;
1244 ref0 = btrfs_item_ptr(leaf, path->slots[0],
1245 struct btrfs_extent_ref_v0);
1246 num_refs = btrfs_ref_count_v0(leaf, ref0);
1247 #endif
1248 } else {
1249 WARN_ON(1);
1250 }
1251 return num_refs;
1252 }
1253
1254 static noinline int lookup_tree_block_ref(struct btrfs_trans_handle *trans,
1255 struct btrfs_root *root,
1256 struct btrfs_path *path,
1257 u64 bytenr, u64 parent,
1258 u64 root_objectid)
1259 {
1260 struct btrfs_key key;
1261 int ret;
1262
1263 key.objectid = bytenr;
1264 if (parent) {
1265 key.type = BTRFS_SHARED_BLOCK_REF_KEY;
1266 key.offset = parent;
1267 } else {
1268 key.type = BTRFS_TREE_BLOCK_REF_KEY;
1269 key.offset = root_objectid;
1270 }
1271
1272 ret = btrfs_search_slot(trans, root, &key, path, -1, 1);
1273 if (ret > 0)
1274 ret = -ENOENT;
1275 #ifdef BTRFS_COMPAT_EXTENT_TREE_V0
1276 if (ret == -ENOENT && parent) {
1277 btrfs_release_path(root, path);
1278 key.type = BTRFS_EXTENT_REF_V0_KEY;
1279 ret = btrfs_search_slot(trans, root, &key, path, -1, 1);
1280 if (ret > 0)
1281 ret = -ENOENT;
1282 }
1283 #endif
1284 return ret;
1285 }
1286
1287 static noinline int insert_tree_block_ref(struct btrfs_trans_handle *trans,
1288 struct btrfs_root *root,
1289 struct btrfs_path *path,
1290 u64 bytenr, u64 parent,
1291 u64 root_objectid)
1292 {
1293 struct btrfs_key key;
1294 int ret;
1295
1296 key.objectid = bytenr;
1297 if (parent) {
1298 key.type = BTRFS_SHARED_BLOCK_REF_KEY;
1299 key.offset = parent;
1300 } else {
1301 key.type = BTRFS_TREE_BLOCK_REF_KEY;
1302 key.offset = root_objectid;
1303 }
1304
1305 ret = btrfs_insert_empty_item(trans, root, path, &key, 0);
1306 btrfs_release_path(root, path);
1307 return ret;
1308 }
1309
1310 static inline int extent_ref_type(u64 parent, u64 owner)
1311 {
1312 int type;
1313 if (owner < BTRFS_FIRST_FREE_OBJECTID) {
1314 if (parent > 0)
1315 type = BTRFS_SHARED_BLOCK_REF_KEY;
1316 else
1317 type = BTRFS_TREE_BLOCK_REF_KEY;
1318 } else {
1319 if (parent > 0)
1320 type = BTRFS_SHARED_DATA_REF_KEY;
1321 else
1322 type = BTRFS_EXTENT_DATA_REF_KEY;
1323 }
1324 return type;
1325 }
1326
1327 static int find_next_key(struct btrfs_path *path, int level,
1328 struct btrfs_key *key)
1329
1330 {
1331 for (; level < BTRFS_MAX_LEVEL; level++) {
1332 if (!path->nodes[level])
1333 break;
1334 if (path->slots[level] + 1 >=
1335 btrfs_header_nritems(path->nodes[level]))
1336 continue;
1337 if (level == 0)
1338 btrfs_item_key_to_cpu(path->nodes[level], key,
1339 path->slots[level] + 1);
1340 else
1341 btrfs_node_key_to_cpu(path->nodes[level], key,
1342 path->slots[level] + 1);
1343 return 0;
1344 }
1345 return 1;
1346 }
1347
1348 /*
1349 * look for inline back ref. if back ref is found, *ref_ret is set
1350 * to the address of inline back ref, and 0 is returned.
1351 *
1352 * if back ref isn't found, *ref_ret is set to the address where it
1353 * should be inserted, and -ENOENT is returned.
1354 *
1355 * if insert is true and there are too many inline back refs, the path
1356 * points to the extent item, and -EAGAIN is returned.
1357 *
1358 * NOTE: inline back refs are ordered in the same way that back ref
1359 * items in the tree are ordered.
1360 */
1361 static noinline_for_stack
1362 int lookup_inline_extent_backref(struct btrfs_trans_handle *trans,
1363 struct btrfs_root *root,
1364 struct btrfs_path *path,
1365 struct btrfs_extent_inline_ref **ref_ret,
1366 u64 bytenr, u64 num_bytes,
1367 u64 parent, u64 root_objectid,
1368 u64 owner, u64 offset, int insert)
1369 {
1370 struct btrfs_key key;
1371 struct extent_buffer *leaf;
1372 struct btrfs_extent_item *ei;
1373 struct btrfs_extent_inline_ref *iref;
1374 u64 flags;
1375 u64 item_size;
1376 unsigned long ptr;
1377 unsigned long end;
1378 int extra_size;
1379 int type;
1380 int want;
1381 int ret;
1382 int err = 0;
1383
1384 key.objectid = bytenr;
1385 key.type = BTRFS_EXTENT_ITEM_KEY;
1386 key.offset = num_bytes;
1387
1388 want = extent_ref_type(parent, owner);
1389 if (insert) {
1390 extra_size = btrfs_extent_inline_ref_size(want);
1391 path->keep_locks = 1;
1392 } else
1393 extra_size = -1;
1394 ret = btrfs_search_slot(trans, root, &key, path, extra_size, 1);
1395 if (ret < 0) {
1396 err = ret;
1397 goto out;
1398 }
1399 BUG_ON(ret);
1400
1401 leaf = path->nodes[0];
1402 item_size = btrfs_item_size_nr(leaf, path->slots[0]);
1403 #ifdef BTRFS_COMPAT_EXTENT_TREE_V0
1404 if (item_size < sizeof(*ei)) {
1405 if (!insert) {
1406 err = -ENOENT;
1407 goto out;
1408 }
1409 ret = convert_extent_item_v0(trans, root, path, owner,
1410 extra_size);
1411 if (ret < 0) {
1412 err = ret;
1413 goto out;
1414 }
1415 leaf = path->nodes[0];
1416 item_size = btrfs_item_size_nr(leaf, path->slots[0]);
1417 }
1418 #endif
1419 BUG_ON(item_size < sizeof(*ei));
1420
1421 ei = btrfs_item_ptr(leaf, path->slots[0], struct btrfs_extent_item);
1422 flags = btrfs_extent_flags(leaf, ei);
1423
1424 ptr = (unsigned long)(ei + 1);
1425 end = (unsigned long)ei + item_size;
1426
1427 if (flags & BTRFS_EXTENT_FLAG_TREE_BLOCK) {
1428 ptr += sizeof(struct btrfs_tree_block_info);
1429 BUG_ON(ptr > end);
1430 } else {
1431 BUG_ON(!(flags & BTRFS_EXTENT_FLAG_DATA));
1432 }
1433
1434 err = -ENOENT;
1435 while (1) {
1436 if (ptr >= end) {
1437 WARN_ON(ptr > end);
1438 break;
1439 }
1440 iref = (struct btrfs_extent_inline_ref *)ptr;
1441 type = btrfs_extent_inline_ref_type(leaf, iref);
1442 if (want < type)
1443 break;
1444 if (want > type) {
1445 ptr += btrfs_extent_inline_ref_size(type);
1446 continue;
1447 }
1448
1449 if (type == BTRFS_EXTENT_DATA_REF_KEY) {
1450 struct btrfs_extent_data_ref *dref;
1451 dref = (struct btrfs_extent_data_ref *)(&iref->offset);
1452 if (match_extent_data_ref(leaf, dref, root_objectid,
1453 owner, offset)) {
1454 err = 0;
1455 break;
1456 }
1457 if (hash_extent_data_ref_item(leaf, dref) <
1458 hash_extent_data_ref(root_objectid, owner, offset))
1459 break;
1460 } else {
1461 u64 ref_offset;
1462 ref_offset = btrfs_extent_inline_ref_offset(leaf, iref);
1463 if (parent > 0) {
1464 if (parent == ref_offset) {
1465 err = 0;
1466 break;
1467 }
1468 if (ref_offset < parent)
1469 break;
1470 } else {
1471 if (root_objectid == ref_offset) {
1472 err = 0;
1473 break;
1474 }
1475 if (ref_offset < root_objectid)
1476 break;
1477 }
1478 }
1479 ptr += btrfs_extent_inline_ref_size(type);
1480 }
1481 if (err == -ENOENT && insert) {
1482 if (item_size + extra_size >=
1483 BTRFS_MAX_EXTENT_ITEM_SIZE(root)) {
1484 err = -EAGAIN;
1485 goto out;
1486 }
1487 /*
1488 * To add new inline back ref, we have to make sure
1489 * there is no corresponding back ref item.
1490 * For simplicity, we just do not add new inline back
1491 * ref if there is any kind of item for this block
1492 */
1493 if (find_next_key(path, 0, &key) == 0 &&
1494 key.objectid == bytenr &&
1495 key.type < BTRFS_BLOCK_GROUP_ITEM_KEY) {
1496 err = -EAGAIN;
1497 goto out;
1498 }
1499 }
1500 *ref_ret = (struct btrfs_extent_inline_ref *)ptr;
1501 out:
1502 if (insert) {
1503 path->keep_locks = 0;
1504 btrfs_unlock_up_safe(path, 1);
1505 }
1506 return err;
1507 }
1508
1509 /*
1510 * helper to add new inline back ref
1511 */
1512 static noinline_for_stack
1513 int setup_inline_extent_backref(struct btrfs_trans_handle *trans,
1514 struct btrfs_root *root,
1515 struct btrfs_path *path,
1516 struct btrfs_extent_inline_ref *iref,
1517 u64 parent, u64 root_objectid,
1518 u64 owner, u64 offset, int refs_to_add,
1519 struct btrfs_delayed_extent_op *extent_op)
1520 {
1521 struct extent_buffer *leaf;
1522 struct btrfs_extent_item *ei;
1523 unsigned long ptr;
1524 unsigned long end;
1525 unsigned long item_offset;
1526 u64 refs;
1527 int size;
1528 int type;
1529 int ret;
1530
1531 leaf = path->nodes[0];
1532 ei = btrfs_item_ptr(leaf, path->slots[0], struct btrfs_extent_item);
1533 item_offset = (unsigned long)iref - (unsigned long)ei;
1534
1535 type = extent_ref_type(parent, owner);
1536 size = btrfs_extent_inline_ref_size(type);
1537
1538 ret = btrfs_extend_item(trans, root, path, size);
1539 BUG_ON(ret);
1540
1541 ei = btrfs_item_ptr(leaf, path->slots[0], struct btrfs_extent_item);
1542 refs = btrfs_extent_refs(leaf, ei);
1543 refs += refs_to_add;
1544 btrfs_set_extent_refs(leaf, ei, refs);
1545 if (extent_op)
1546 __run_delayed_extent_op(extent_op, leaf, ei);
1547
1548 ptr = (unsigned long)ei + item_offset;
1549 end = (unsigned long)ei + btrfs_item_size_nr(leaf, path->slots[0]);
1550 if (ptr < end - size)
1551 memmove_extent_buffer(leaf, ptr + size, ptr,
1552 end - size - ptr);
1553
1554 iref = (struct btrfs_extent_inline_ref *)ptr;
1555 btrfs_set_extent_inline_ref_type(leaf, iref, type);
1556 if (type == BTRFS_EXTENT_DATA_REF_KEY) {
1557 struct btrfs_extent_data_ref *dref;
1558 dref = (struct btrfs_extent_data_ref *)(&iref->offset);
1559 btrfs_set_extent_data_ref_root(leaf, dref, root_objectid);
1560 btrfs_set_extent_data_ref_objectid(leaf, dref, owner);
1561 btrfs_set_extent_data_ref_offset(leaf, dref, offset);
1562 btrfs_set_extent_data_ref_count(leaf, dref, refs_to_add);
1563 } else if (type == BTRFS_SHARED_DATA_REF_KEY) {
1564 struct btrfs_shared_data_ref *sref;
1565 sref = (struct btrfs_shared_data_ref *)(iref + 1);
1566 btrfs_set_shared_data_ref_count(leaf, sref, refs_to_add);
1567 btrfs_set_extent_inline_ref_offset(leaf, iref, parent);
1568 } else if (type == BTRFS_SHARED_BLOCK_REF_KEY) {
1569 btrfs_set_extent_inline_ref_offset(leaf, iref, parent);
1570 } else {
1571 btrfs_set_extent_inline_ref_offset(leaf, iref, root_objectid);
1572 }
1573 btrfs_mark_buffer_dirty(leaf);
1574 return 0;
1575 }
1576
1577 static int lookup_extent_backref(struct btrfs_trans_handle *trans,
1578 struct btrfs_root *root,
1579 struct btrfs_path *path,
1580 struct btrfs_extent_inline_ref **ref_ret,
1581 u64 bytenr, u64 num_bytes, u64 parent,
1582 u64 root_objectid, u64 owner, u64 offset)
1583 {
1584 int ret;
1585
1586 ret = lookup_inline_extent_backref(trans, root, path, ref_ret,
1587 bytenr, num_bytes, parent,
1588 root_objectid, owner, offset, 0);
1589 if (ret != -ENOENT)
1590 return ret;
1591
1592 btrfs_release_path(root, path);
1593 *ref_ret = NULL;
1594
1595 if (owner < BTRFS_FIRST_FREE_OBJECTID) {
1596 ret = lookup_tree_block_ref(trans, root, path, bytenr, parent,
1597 root_objectid);
1598 } else {
1599 ret = lookup_extent_data_ref(trans, root, path, bytenr, parent,
1600 root_objectid, owner, offset);
1601 }
1602 return ret;
1603 }
1604
1605 /*
1606 * helper to update/remove inline back ref
1607 */
1608 static noinline_for_stack
1609 int update_inline_extent_backref(struct btrfs_trans_handle *trans,
1610 struct btrfs_root *root,
1611 struct btrfs_path *path,
1612 struct btrfs_extent_inline_ref *iref,
1613 int refs_to_mod,
1614 struct btrfs_delayed_extent_op *extent_op)
1615 {
1616 struct extent_buffer *leaf;
1617 struct btrfs_extent_item *ei;
1618 struct btrfs_extent_data_ref *dref = NULL;
1619 struct btrfs_shared_data_ref *sref = NULL;
1620 unsigned long ptr;
1621 unsigned long end;
1622 u32 item_size;
1623 int size;
1624 int type;
1625 int ret;
1626 u64 refs;
1627
1628 leaf = path->nodes[0];
1629 ei = btrfs_item_ptr(leaf, path->slots[0], struct btrfs_extent_item);
1630 refs = btrfs_extent_refs(leaf, ei);
1631 WARN_ON(refs_to_mod < 0 && refs + refs_to_mod <= 0);
1632 refs += refs_to_mod;
1633 btrfs_set_extent_refs(leaf, ei, refs);
1634 if (extent_op)
1635 __run_delayed_extent_op(extent_op, leaf, ei);
1636
1637 type = btrfs_extent_inline_ref_type(leaf, iref);
1638
1639 if (type == BTRFS_EXTENT_DATA_REF_KEY) {
1640 dref = (struct btrfs_extent_data_ref *)(&iref->offset);
1641 refs = btrfs_extent_data_ref_count(leaf, dref);
1642 } else if (type == BTRFS_SHARED_DATA_REF_KEY) {
1643 sref = (struct btrfs_shared_data_ref *)(iref + 1);
1644 refs = btrfs_shared_data_ref_count(leaf, sref);
1645 } else {
1646 refs = 1;
1647 BUG_ON(refs_to_mod != -1);
1648 }
1649
1650 BUG_ON(refs_to_mod < 0 && refs < -refs_to_mod);
1651 refs += refs_to_mod;
1652
1653 if (refs > 0) {
1654 if (type == BTRFS_EXTENT_DATA_REF_KEY)
1655 btrfs_set_extent_data_ref_count(leaf, dref, refs);
1656 else
1657 btrfs_set_shared_data_ref_count(leaf, sref, refs);
1658 } else {
1659 size = btrfs_extent_inline_ref_size(type);
1660 item_size = btrfs_item_size_nr(leaf, path->slots[0]);
1661 ptr = (unsigned long)iref;
1662 end = (unsigned long)ei + item_size;
1663 if (ptr + size < end)
1664 memmove_extent_buffer(leaf, ptr, ptr + size,
1665 end - ptr - size);
1666 item_size -= size;
1667 ret = btrfs_truncate_item(trans, root, path, item_size, 1);
1668 BUG_ON(ret);
1669 }
1670 btrfs_mark_buffer_dirty(leaf);
1671 return 0;
1672 }
1673
1674 static noinline_for_stack
1675 int insert_inline_extent_backref(struct btrfs_trans_handle *trans,
1676 struct btrfs_root *root,
1677 struct btrfs_path *path,
1678 u64 bytenr, u64 num_bytes, u64 parent,
1679 u64 root_objectid, u64 owner,
1680 u64 offset, int refs_to_add,
1681 struct btrfs_delayed_extent_op *extent_op)
1682 {
1683 struct btrfs_extent_inline_ref *iref;
1684 int ret;
1685
1686 ret = lookup_inline_extent_backref(trans, root, path, &iref,
1687 bytenr, num_bytes, parent,
1688 root_objectid, owner, offset, 1);
1689 if (ret == 0) {
1690 BUG_ON(owner < BTRFS_FIRST_FREE_OBJECTID);
1691 ret = update_inline_extent_backref(trans, root, path, iref,
1692 refs_to_add, extent_op);
1693 } else if (ret == -ENOENT) {
1694 ret = setup_inline_extent_backref(trans, root, path, iref,
1695 parent, root_objectid,
1696 owner, offset, refs_to_add,
1697 extent_op);
1698 }
1699 return ret;
1700 }
1701
1702 static int insert_extent_backref(struct btrfs_trans_handle *trans,
1703 struct btrfs_root *root,
1704 struct btrfs_path *path,
1705 u64 bytenr, u64 parent, u64 root_objectid,
1706 u64 owner, u64 offset, int refs_to_add)
1707 {
1708 int ret;
1709 if (owner < BTRFS_FIRST_FREE_OBJECTID) {
1710 BUG_ON(refs_to_add != 1);
1711 ret = insert_tree_block_ref(trans, root, path, bytenr,
1712 parent, root_objectid);
1713 } else {
1714 ret = insert_extent_data_ref(trans, root, path, bytenr,
1715 parent, root_objectid,
1716 owner, offset, refs_to_add);
1717 }
1718 return ret;
1719 }
1720
1721 static int remove_extent_backref(struct btrfs_trans_handle *trans,
1722 struct btrfs_root *root,
1723 struct btrfs_path *path,
1724 struct btrfs_extent_inline_ref *iref,
1725 int refs_to_drop, int is_data)
1726 {
1727 int ret;
1728
1729 BUG_ON(!is_data && refs_to_drop != 1);
1730 if (iref) {
1731 ret = update_inline_extent_backref(trans, root, path, iref,
1732 -refs_to_drop, NULL);
1733 } else if (is_data) {
1734 ret = remove_extent_data_ref(trans, root, path, refs_to_drop);
1735 } else {
1736 ret = btrfs_del_item(trans, root, path);
1737 }
1738 return ret;
1739 }
1740
1741 static int btrfs_issue_discard(struct block_device *bdev,
1742 u64 start, u64 len)
1743 {
1744 return blkdev_issue_discard(bdev, start >> 9, len >> 9, GFP_NOFS, 0);
1745 }
1746
1747 static int btrfs_discard_extent(struct btrfs_root *root, u64 bytenr,
1748 u64 num_bytes, u64 *actual_bytes)
1749 {
1750 int ret;
1751 u64 discarded_bytes = 0;
1752 struct btrfs_multi_bio *multi = NULL;
1753
1754
1755 /* Tell the block device(s) that the sectors can be discarded */
1756 ret = btrfs_map_block(&root->fs_info->mapping_tree, REQ_DISCARD,
1757 bytenr, &num_bytes, &multi, 0);
1758 if (!ret) {
1759 struct btrfs_bio_stripe *stripe = multi->stripes;
1760 int i;
1761
1762
1763 for (i = 0; i < multi->num_stripes; i++, stripe++) {
1764 ret = btrfs_issue_discard(stripe->dev->bdev,
1765 stripe->physical,
1766 stripe->length);
1767 if (!ret)
1768 discarded_bytes += stripe->length;
1769 else if (ret != -EOPNOTSUPP)
1770 break;
1771 }
1772 kfree(multi);
1773 }
1774 if (discarded_bytes && ret == -EOPNOTSUPP)
1775 ret = 0;
1776
1777 if (actual_bytes)
1778 *actual_bytes = discarded_bytes;
1779
1780
1781 return ret;
1782 }
1783
1784 int btrfs_inc_extent_ref(struct btrfs_trans_handle *trans,
1785 struct btrfs_root *root,
1786 u64 bytenr, u64 num_bytes, u64 parent,
1787 u64 root_objectid, u64 owner, u64 offset)
1788 {
1789 int ret;
1790 BUG_ON(owner < BTRFS_FIRST_FREE_OBJECTID &&
1791 root_objectid == BTRFS_TREE_LOG_OBJECTID);
1792
1793 if (owner < BTRFS_FIRST_FREE_OBJECTID) {
1794 ret = btrfs_add_delayed_tree_ref(trans, bytenr, num_bytes,
1795 parent, root_objectid, (int)owner,
1796 BTRFS_ADD_DELAYED_REF, NULL);
1797 } else {
1798 ret = btrfs_add_delayed_data_ref(trans, bytenr, num_bytes,
1799 parent, root_objectid, owner, offset,
1800 BTRFS_ADD_DELAYED_REF, NULL);
1801 }
1802 return ret;
1803 }
1804
1805 static int __btrfs_inc_extent_ref(struct btrfs_trans_handle *trans,
1806 struct btrfs_root *root,
1807 u64 bytenr, u64 num_bytes,
1808 u64 parent, u64 root_objectid,
1809 u64 owner, u64 offset, int refs_to_add,
1810 struct btrfs_delayed_extent_op *extent_op)
1811 {
1812 struct btrfs_path *path;
1813 struct extent_buffer *leaf;
1814 struct btrfs_extent_item *item;
1815 u64 refs;
1816 int ret;
1817 int err = 0;
1818
1819 path = btrfs_alloc_path();
1820 if (!path)
1821 return -ENOMEM;
1822
1823 path->reada = 1;
1824 path->leave_spinning = 1;
1825 /* this will setup the path even if it fails to insert the back ref */
1826 ret = insert_inline_extent_backref(trans, root->fs_info->extent_root,
1827 path, bytenr, num_bytes, parent,
1828 root_objectid, owner, offset,
1829 refs_to_add, extent_op);
1830 if (ret == 0)
1831 goto out;
1832
1833 if (ret != -EAGAIN) {
1834 err = ret;
1835 goto out;
1836 }
1837
1838 leaf = path->nodes[0];
1839 item = btrfs_item_ptr(leaf, path->slots[0], struct btrfs_extent_item);
1840 refs = btrfs_extent_refs(leaf, item);
1841 btrfs_set_extent_refs(leaf, item, refs + refs_to_add);
1842 if (extent_op)
1843 __run_delayed_extent_op(extent_op, leaf, item);
1844
1845 btrfs_mark_buffer_dirty(leaf);
1846 btrfs_release_path(root->fs_info->extent_root, path);
1847
1848 path->reada = 1;
1849 path->leave_spinning = 1;
1850
1851 /* now insert the actual backref */
1852 ret = insert_extent_backref(trans, root->fs_info->extent_root,
1853 path, bytenr, parent, root_objectid,
1854 owner, offset, refs_to_add);
1855 BUG_ON(ret);
1856 out:
1857 btrfs_free_path(path);
1858 return err;
1859 }
1860
1861 static int run_delayed_data_ref(struct btrfs_trans_handle *trans,
1862 struct btrfs_root *root,
1863 struct btrfs_delayed_ref_node *node,
1864 struct btrfs_delayed_extent_op *extent_op,
1865 int insert_reserved)
1866 {
1867 int ret = 0;
1868 struct btrfs_delayed_data_ref *ref;
1869 struct btrfs_key ins;
1870 u64 parent = 0;
1871 u64 ref_root = 0;
1872 u64 flags = 0;
1873
1874 ins.objectid = node->bytenr;
1875 ins.offset = node->num_bytes;
1876 ins.type = BTRFS_EXTENT_ITEM_KEY;
1877
1878 ref = btrfs_delayed_node_to_data_ref(node);
1879 if (node->type == BTRFS_SHARED_DATA_REF_KEY)
1880 parent = ref->parent;
1881 else
1882 ref_root = ref->root;
1883
1884 if (node->action == BTRFS_ADD_DELAYED_REF && insert_reserved) {
1885 if (extent_op) {
1886 BUG_ON(extent_op->update_key);
1887 flags |= extent_op->flags_to_set;
1888 }
1889 ret = alloc_reserved_file_extent(trans, root,
1890 parent, ref_root, flags,
1891 ref->objectid, ref->offset,
1892 &ins, node->ref_mod);
1893 } else if (node->action == BTRFS_ADD_DELAYED_REF) {
1894 ret = __btrfs_inc_extent_ref(trans, root, node->bytenr,
1895 node->num_bytes, parent,
1896 ref_root, ref->objectid,
1897 ref->offset, node->ref_mod,
1898 extent_op);
1899 } else if (node->action == BTRFS_DROP_DELAYED_REF) {
1900 ret = __btrfs_free_extent(trans, root, node->bytenr,
1901 node->num_bytes, parent,
1902 ref_root, ref->objectid,
1903 ref->offset, node->ref_mod,
1904 extent_op);
1905 } else {
1906 BUG();
1907 }
1908 return ret;
1909 }
1910
1911 static void __run_delayed_extent_op(struct btrfs_delayed_extent_op *extent_op,
1912 struct extent_buffer *leaf,
1913 struct btrfs_extent_item *ei)
1914 {
1915 u64 flags = btrfs_extent_flags(leaf, ei);
1916 if (extent_op->update_flags) {
1917 flags |= extent_op->flags_to_set;
1918 btrfs_set_extent_flags(leaf, ei, flags);
1919 }
1920
1921 if (extent_op->update_key) {
1922 struct btrfs_tree_block_info *bi;
1923 BUG_ON(!(flags & BTRFS_EXTENT_FLAG_TREE_BLOCK));
1924 bi = (struct btrfs_tree_block_info *)(ei + 1);
1925 btrfs_set_tree_block_key(leaf, bi, &extent_op->key);
1926 }
1927 }
1928
1929 static int run_delayed_extent_op(struct btrfs_trans_handle *trans,
1930 struct btrfs_root *root,
1931 struct btrfs_delayed_ref_node *node,
1932 struct btrfs_delayed_extent_op *extent_op)
1933 {
1934 struct btrfs_key key;
1935 struct btrfs_path *path;
1936 struct btrfs_extent_item *ei;
1937 struct extent_buffer *leaf;
1938 u32 item_size;
1939 int ret;
1940 int err = 0;
1941
1942 path = btrfs_alloc_path();
1943 if (!path)
1944 return -ENOMEM;
1945
1946 key.objectid = node->bytenr;
1947 key.type = BTRFS_EXTENT_ITEM_KEY;
1948 key.offset = node->num_bytes;
1949
1950 path->reada = 1;
1951 path->leave_spinning = 1;
1952 ret = btrfs_search_slot(trans, root->fs_info->extent_root, &key,
1953 path, 0, 1);
1954 if (ret < 0) {
1955 err = ret;
1956 goto out;
1957 }
1958 if (ret > 0) {
1959 err = -EIO;
1960 goto out;
1961 }
1962
1963 leaf = path->nodes[0];
1964 item_size = btrfs_item_size_nr(leaf, path->slots[0]);
1965 #ifdef BTRFS_COMPAT_EXTENT_TREE_V0
1966 if (item_size < sizeof(*ei)) {
1967 ret = convert_extent_item_v0(trans, root->fs_info->extent_root,
1968 path, (u64)-1, 0);
1969 if (ret < 0) {
1970 err = ret;
1971 goto out;
1972 }
1973 leaf = path->nodes[0];
1974 item_size = btrfs_item_size_nr(leaf, path->slots[0]);
1975 }
1976 #endif
1977 BUG_ON(item_size < sizeof(*ei));
1978 ei = btrfs_item_ptr(leaf, path->slots[0], struct btrfs_extent_item);
1979 __run_delayed_extent_op(extent_op, leaf, ei);
1980
1981 btrfs_mark_buffer_dirty(leaf);
1982 out:
1983 btrfs_free_path(path);
1984 return err;
1985 }
1986
1987 static int run_delayed_tree_ref(struct btrfs_trans_handle *trans,
1988 struct btrfs_root *root,
1989 struct btrfs_delayed_ref_node *node,
1990 struct btrfs_delayed_extent_op *extent_op,
1991 int insert_reserved)
1992 {
1993 int ret = 0;
1994 struct btrfs_delayed_tree_ref *ref;
1995 struct btrfs_key ins;
1996 u64 parent = 0;
1997 u64 ref_root = 0;
1998
1999 ins.objectid = node->bytenr;
2000 ins.offset = node->num_bytes;
2001 ins.type = BTRFS_EXTENT_ITEM_KEY;
2002
2003 ref = btrfs_delayed_node_to_tree_ref(node);
2004 if (node->type == BTRFS_SHARED_BLOCK_REF_KEY)
2005 parent = ref->parent;
2006 else
2007 ref_root = ref->root;
2008
2009 BUG_ON(node->ref_mod != 1);
2010 if (node->action == BTRFS_ADD_DELAYED_REF && insert_reserved) {
2011 BUG_ON(!extent_op || !extent_op->update_flags ||
2012 !extent_op->update_key);
2013 ret = alloc_reserved_tree_block(trans, root,
2014 parent, ref_root,
2015 extent_op->flags_to_set,
2016 &extent_op->key,
2017 ref->level, &ins);
2018 } else if (node->action == BTRFS_ADD_DELAYED_REF) {
2019 ret = __btrfs_inc_extent_ref(trans, root, node->bytenr,
2020 node->num_bytes, parent, ref_root,
2021 ref->level, 0, 1, extent_op);
2022 } else if (node->action == BTRFS_DROP_DELAYED_REF) {
2023 ret = __btrfs_free_extent(trans, root, node->bytenr,
2024 node->num_bytes, parent, ref_root,
2025 ref->level, 0, 1, extent_op);
2026 } else {
2027 BUG();
2028 }
2029 return ret;
2030 }
2031
2032 /* helper function to actually process a single delayed ref entry */
2033 static int run_one_delayed_ref(struct btrfs_trans_handle *trans,
2034 struct btrfs_root *root,
2035 struct btrfs_delayed_ref_node *node,
2036 struct btrfs_delayed_extent_op *extent_op,
2037 int insert_reserved)
2038 {
2039 int ret;
2040 if (btrfs_delayed_ref_is_head(node)) {
2041 struct btrfs_delayed_ref_head *head;
2042 /*
2043 * we've hit the end of the chain and we were supposed
2044 * to insert this extent into the tree. But, it got
2045 * deleted before we ever needed to insert it, so all
2046 * we have to do is clean up the accounting
2047 */
2048 BUG_ON(extent_op);
2049 head = btrfs_delayed_node_to_head(node);
2050 if (insert_reserved) {
2051 btrfs_pin_extent(root, node->bytenr,
2052 node->num_bytes, 1);
2053 if (head->is_data) {
2054 ret = btrfs_del_csums(trans, root,
2055 node->bytenr,
2056 node->num_bytes);
2057 BUG_ON(ret);
2058 }
2059 }
2060 mutex_unlock(&head->mutex);
2061 return 0;
2062 }
2063
2064 if (node->type == BTRFS_TREE_BLOCK_REF_KEY ||
2065 node->type == BTRFS_SHARED_BLOCK_REF_KEY)
2066 ret = run_delayed_tree_ref(trans, root, node, extent_op,
2067 insert_reserved);
2068 else if (node->type == BTRFS_EXTENT_DATA_REF_KEY ||
2069 node->type == BTRFS_SHARED_DATA_REF_KEY)
2070 ret = run_delayed_data_ref(trans, root, node, extent_op,
2071 insert_reserved);
2072 else
2073 BUG();
2074 return ret;
2075 }
2076
2077 static noinline struct btrfs_delayed_ref_node *
2078 select_delayed_ref(struct btrfs_delayed_ref_head *head)
2079 {
2080 struct rb_node *node;
2081 struct btrfs_delayed_ref_node *ref;
2082 int action = BTRFS_ADD_DELAYED_REF;
2083 again:
2084 /*
2085 * select delayed ref of type BTRFS_ADD_DELAYED_REF first.
2086 * this prevents ref count from going down to zero when
2087 * there still are pending delayed ref.
2088 */
2089 node = rb_prev(&head->node.rb_node);
2090 while (1) {
2091 if (!node)
2092 break;
2093 ref = rb_entry(node, struct btrfs_delayed_ref_node,
2094 rb_node);
2095 if (ref->bytenr != head->node.bytenr)
2096 break;
2097 if (ref->action == action)
2098 return ref;
2099 node = rb_prev(node);
2100 }
2101 if (action == BTRFS_ADD_DELAYED_REF) {
2102 action = BTRFS_DROP_DELAYED_REF;
2103 goto again;
2104 }
2105 return NULL;
2106 }
2107
2108 static noinline int run_clustered_refs(struct btrfs_trans_handle *trans,
2109 struct btrfs_root *root,
2110 struct list_head *cluster)
2111 {
2112 struct btrfs_delayed_ref_root *delayed_refs;
2113 struct btrfs_delayed_ref_node *ref;
2114 struct btrfs_delayed_ref_head *locked_ref = NULL;
2115 struct btrfs_delayed_extent_op *extent_op;
2116 int ret;
2117 int count = 0;
2118 int must_insert_reserved = 0;
2119
2120 delayed_refs = &trans->transaction->delayed_refs;
2121 while (1) {
2122 if (!locked_ref) {
2123 /* pick a new head ref from the cluster list */
2124 if (list_empty(cluster))
2125 break;
2126
2127 locked_ref = list_entry(cluster->next,
2128 struct btrfs_delayed_ref_head, cluster);
2129
2130 /* grab the lock that says we are going to process
2131 * all the refs for this head */
2132 ret = btrfs_delayed_ref_lock(trans, locked_ref);
2133
2134 /*
2135 * we may have dropped the spin lock to get the head
2136 * mutex lock, and that might have given someone else
2137 * time to free the head. If that's true, it has been
2138 * removed from our list and we can move on.
2139 */
2140 if (ret == -EAGAIN) {
2141 locked_ref = NULL;
2142 count++;
2143 continue;
2144 }
2145 }
2146
2147 /*
2148 * record the must insert reserved flag before we
2149 * drop the spin lock.
2150 */
2151 must_insert_reserved = locked_ref->must_insert_reserved;
2152 locked_ref->must_insert_reserved = 0;
2153
2154 extent_op = locked_ref->extent_op;
2155 locked_ref->extent_op = NULL;
2156
2157 /*
2158 * locked_ref is the head node, so we have to go one
2159 * node back for any delayed ref updates
2160 */
2161 ref = select_delayed_ref(locked_ref);
2162 if (!ref) {
2163 /* All delayed refs have been processed, Go ahead
2164 * and send the head node to run_one_delayed_ref,
2165 * so that any accounting fixes can happen
2166 */
2167 ref = &locked_ref->node;
2168
2169 if (extent_op && must_insert_reserved) {
2170 kfree(extent_op);
2171 extent_op = NULL;
2172 }
2173
2174 if (extent_op) {
2175 spin_unlock(&delayed_refs->lock);
2176
2177 ret = run_delayed_extent_op(trans, root,
2178 ref, extent_op);
2179 BUG_ON(ret);
2180 kfree(extent_op);
2181
2182 cond_resched();
2183 spin_lock(&delayed_refs->lock);
2184 continue;
2185 }
2186
2187 list_del_init(&locked_ref->cluster);
2188 locked_ref = NULL;
2189 }
2190
2191 ref->in_tree = 0;
2192 rb_erase(&ref->rb_node, &delayed_refs->root);
2193 delayed_refs->num_entries--;
2194
2195 spin_unlock(&delayed_refs->lock);
2196
2197 ret = run_one_delayed_ref(trans, root, ref, extent_op,
2198 must_insert_reserved);
2199 BUG_ON(ret);
2200
2201 btrfs_put_delayed_ref(ref);
2202 kfree(extent_op);
2203 count++;
2204
2205 cond_resched();
2206 spin_lock(&delayed_refs->lock);
2207 }
2208 return count;
2209 }
2210
2211 /*
2212 * this starts processing the delayed reference count updates and
2213 * extent insertions we have queued up so far. count can be
2214 * 0, which means to process everything in the tree at the start
2215 * of the run (but not newly added entries), or it can be some target
2216 * number you'd like to process.
2217 */
2218 int btrfs_run_delayed_refs(struct btrfs_trans_handle *trans,
2219 struct btrfs_root *root, unsigned long count)
2220 {
2221 struct rb_node *node;
2222 struct btrfs_delayed_ref_root *delayed_refs;
2223 struct btrfs_delayed_ref_node *ref;
2224 struct list_head cluster;
2225 int ret;
2226 int run_all = count == (unsigned long)-1;
2227 int run_most = 0;
2228
2229 if (root == root->fs_info->extent_root)
2230 root = root->fs_info->tree_root;
2231
2232 delayed_refs = &trans->transaction->delayed_refs;
2233 INIT_LIST_HEAD(&cluster);
2234 again:
2235 spin_lock(&delayed_refs->lock);
2236 if (count == 0) {
2237 count = delayed_refs->num_entries * 2;
2238 run_most = 1;
2239 }
2240 while (1) {
2241 if (!(run_all || run_most) &&
2242 delayed_refs->num_heads_ready < 64)
2243 break;
2244
2245 /*
2246 * go find something we can process in the rbtree. We start at
2247 * the beginning of the tree, and then build a cluster
2248 * of refs to process starting at the first one we are able to
2249 * lock
2250 */
2251 ret = btrfs_find_ref_cluster(trans, &cluster,
2252 delayed_refs->run_delayed_start);
2253 if (ret)
2254 break;
2255
2256 ret = run_clustered_refs(trans, root, &cluster);
2257 BUG_ON(ret < 0);
2258
2259 count -= min_t(unsigned long, ret, count);
2260
2261 if (count == 0)
2262 break;
2263 }
2264
2265 if (run_all) {
2266 node = rb_first(&delayed_refs->root);
2267 if (!node)
2268 goto out;
2269 count = (unsigned long)-1;
2270
2271 while (node) {
2272 ref = rb_entry(node, struct btrfs_delayed_ref_node,
2273 rb_node);
2274 if (btrfs_delayed_ref_is_head(ref)) {
2275 struct btrfs_delayed_ref_head *head;
2276
2277 head = btrfs_delayed_node_to_head(ref);
2278 atomic_inc(&ref->refs);
2279
2280 spin_unlock(&delayed_refs->lock);
2281 mutex_lock(&head->mutex);
2282 mutex_unlock(&head->mutex);
2283
2284 btrfs_put_delayed_ref(ref);
2285 cond_resched();
2286 goto again;
2287 }
2288 node = rb_next(node);
2289 }
2290 spin_unlock(&delayed_refs->lock);
2291 schedule_timeout(1);
2292 goto again;
2293 }
2294 out:
2295 spin_unlock(&delayed_refs->lock);
2296 return 0;
2297 }
2298
2299 int btrfs_set_disk_extent_flags(struct btrfs_trans_handle *trans,
2300 struct btrfs_root *root,
2301 u64 bytenr, u64 num_bytes, u64 flags,
2302 int is_data)
2303 {
2304 struct btrfs_delayed_extent_op *extent_op;
2305 int ret;
2306
2307 extent_op = kmalloc(sizeof(*extent_op), GFP_NOFS);
2308 if (!extent_op)
2309 return -ENOMEM;
2310
2311 extent_op->flags_to_set = flags;
2312 extent_op->update_flags = 1;
2313 extent_op->update_key = 0;
2314 extent_op->is_data = is_data ? 1 : 0;
2315
2316 ret = btrfs_add_delayed_extent_op(trans, bytenr, num_bytes, extent_op);
2317 if (ret)
2318 kfree(extent_op);
2319 return ret;
2320 }
2321
2322 static noinline int check_delayed_ref(struct btrfs_trans_handle *trans,
2323 struct btrfs_root *root,
2324 struct btrfs_path *path,
2325 u64 objectid, u64 offset, u64 bytenr)
2326 {
2327 struct btrfs_delayed_ref_head *head;
2328 struct btrfs_delayed_ref_node *ref;
2329 struct btrfs_delayed_data_ref *data_ref;
2330 struct btrfs_delayed_ref_root *delayed_refs;
2331 struct rb_node *node;
2332 int ret = 0;
2333
2334 ret = -ENOENT;
2335 delayed_refs = &trans->transaction->delayed_refs;
2336 spin_lock(&delayed_refs->lock);
2337 head = btrfs_find_delayed_ref_head(trans, bytenr);
2338 if (!head)
2339 goto out;
2340
2341 if (!mutex_trylock(&head->mutex)) {
2342 atomic_inc(&head->node.refs);
2343 spin_unlock(&delayed_refs->lock);
2344
2345 btrfs_release_path(root->fs_info->extent_root, path);
2346
2347 mutex_lock(&head->mutex);
2348 mutex_unlock(&head->mutex);
2349 btrfs_put_delayed_ref(&head->node);
2350 return -EAGAIN;
2351 }
2352
2353 node = rb_prev(&head->node.rb_node);
2354 if (!node)
2355 goto out_unlock;
2356
2357 ref = rb_entry(node, struct btrfs_delayed_ref_node, rb_node);
2358
2359 if (ref->bytenr != bytenr)
2360 goto out_unlock;
2361
2362 ret = 1;
2363 if (ref->type != BTRFS_EXTENT_DATA_REF_KEY)
2364 goto out_unlock;
2365
2366 data_ref = btrfs_delayed_node_to_data_ref(ref);
2367
2368 node = rb_prev(node);
2369 if (node) {
2370 ref = rb_entry(node, struct btrfs_delayed_ref_node, rb_node);
2371 if (ref->bytenr == bytenr)
2372 goto out_unlock;
2373 }
2374
2375 if (data_ref->root != root->root_key.objectid ||
2376 data_ref->objectid != objectid || data_ref->offset != offset)
2377 goto out_unlock;
2378
2379 ret = 0;
2380 out_unlock:
2381 mutex_unlock(&head->mutex);
2382 out:
2383 spin_unlock(&delayed_refs->lock);
2384 return ret;
2385 }
2386
2387 static noinline int check_committed_ref(struct btrfs_trans_handle *trans,
2388 struct btrfs_root *root,
2389 struct btrfs_path *path,
2390 u64 objectid, u64 offset, u64 bytenr)
2391 {
2392 struct btrfs_root *extent_root = root->fs_info->extent_root;
2393 struct extent_buffer *leaf;
2394 struct btrfs_extent_data_ref *ref;
2395 struct btrfs_extent_inline_ref *iref;
2396 struct btrfs_extent_item *ei;
2397 struct btrfs_key key;
2398 u32 item_size;
2399 int ret;
2400
2401 key.objectid = bytenr;
2402 key.offset = (u64)-1;
2403 key.type = BTRFS_EXTENT_ITEM_KEY;
2404
2405 ret = btrfs_search_slot(NULL, extent_root, &key, path, 0, 0);
2406 if (ret < 0)
2407 goto out;
2408 BUG_ON(ret == 0);
2409
2410 ret = -ENOENT;
2411 if (path->slots[0] == 0)
2412 goto out;
2413
2414 path->slots[0]--;
2415 leaf = path->nodes[0];
2416 btrfs_item_key_to_cpu(leaf, &key, path->slots[0]);
2417
2418 if (key.objectid != bytenr || key.type != BTRFS_EXTENT_ITEM_KEY)
2419 goto out;
2420
2421 ret = 1;
2422 item_size = btrfs_item_size_nr(leaf, path->slots[0]);
2423 #ifdef BTRFS_COMPAT_EXTENT_TREE_V0
2424 if (item_size < sizeof(*ei)) {
2425 WARN_ON(item_size != sizeof(struct btrfs_extent_item_v0));
2426 goto out;
2427 }
2428 #endif
2429 ei = btrfs_item_ptr(leaf, path->slots[0], struct btrfs_extent_item);
2430
2431 if (item_size != sizeof(*ei) +
2432 btrfs_extent_inline_ref_size(BTRFS_EXTENT_DATA_REF_KEY))
2433 goto out;
2434
2435 if (btrfs_extent_generation(leaf, ei) <=
2436 btrfs_root_last_snapshot(&root->root_item))
2437 goto out;
2438
2439 iref = (struct btrfs_extent_inline_ref *)(ei + 1);
2440 if (btrfs_extent_inline_ref_type(leaf, iref) !=
2441 BTRFS_EXTENT_DATA_REF_KEY)
2442 goto out;
2443
2444 ref = (struct btrfs_extent_data_ref *)(&iref->offset);
2445 if (btrfs_extent_refs(leaf, ei) !=
2446 btrfs_extent_data_ref_count(leaf, ref) ||
2447 btrfs_extent_data_ref_root(leaf, ref) !=
2448 root->root_key.objectid ||
2449 btrfs_extent_data_ref_objectid(leaf, ref) != objectid ||
2450 btrfs_extent_data_ref_offset(leaf, ref) != offset)
2451 goto out;
2452
2453 ret = 0;
2454 out:
2455 return ret;
2456 }
2457
2458 int btrfs_cross_ref_exist(struct btrfs_trans_handle *trans,
2459 struct btrfs_root *root,
2460 u64 objectid, u64 offset, u64 bytenr)
2461 {
2462 struct btrfs_path *path;
2463 int ret;
2464 int ret2;
2465
2466 path = btrfs_alloc_path();
2467 if (!path)
2468 return -ENOENT;
2469
2470 do {
2471 ret = check_committed_ref(trans, root, path, objectid,
2472 offset, bytenr);
2473 if (ret && ret != -ENOENT)
2474 goto out;
2475
2476 ret2 = check_delayed_ref(trans, root, path, objectid,
2477 offset, bytenr);
2478 } while (ret2 == -EAGAIN);
2479
2480 if (ret2 && ret2 != -ENOENT) {
2481 ret = ret2;
2482 goto out;
2483 }
2484
2485 if (ret != -ENOENT || ret2 != -ENOENT)
2486 ret = 0;
2487 out:
2488 btrfs_free_path(path);
2489 if (root->root_key.objectid == BTRFS_DATA_RELOC_TREE_OBJECTID)
2490 WARN_ON(ret > 0);
2491 return ret;
2492 }
2493
2494 #if 0
2495 int btrfs_cache_ref(struct btrfs_trans_handle *trans, struct btrfs_root *root,
2496 struct extent_buffer *buf, u32 nr_extents)
2497 {
2498 struct btrfs_key key;
2499 struct btrfs_file_extent_item *fi;
2500 u64 root_gen;
2501 u32 nritems;
2502 int i;
2503 int level;
2504 int ret = 0;
2505 int shared = 0;
2506
2507 if (!root->ref_cows)
2508 return 0;
2509
2510 if (root->root_key.objectid != BTRFS_TREE_RELOC_OBJECTID) {
2511 shared = 0;
2512 root_gen = root->root_key.offset;
2513 } else {
2514 shared = 1;
2515 root_gen = trans->transid - 1;
2516 }
2517
2518 level = btrfs_header_level(buf);
2519 nritems = btrfs_header_nritems(buf);
2520
2521 if (level == 0) {
2522 struct btrfs_leaf_ref *ref;
2523 struct btrfs_extent_info *info;
2524
2525 ref = btrfs_alloc_leaf_ref(root, nr_extents);
2526 if (!ref) {
2527 ret = -ENOMEM;
2528 goto out;
2529 }
2530
2531 ref->root_gen = root_gen;
2532 ref->bytenr = buf->start;
2533 ref->owner = btrfs_header_owner(buf);
2534 ref->generation = btrfs_header_generation(buf);
2535 ref->nritems = nr_extents;
2536 info = ref->extents;
2537
2538 for (i = 0; nr_extents > 0 && i < nritems; i++) {
2539 u64 disk_bytenr;
2540 btrfs_item_key_to_cpu(buf, &key, i);
2541 if (btrfs_key_type(&key) != BTRFS_EXTENT_DATA_KEY)
2542 continue;
2543 fi = btrfs_item_ptr(buf, i,
2544 struct btrfs_file_extent_item);
2545 if (btrfs_file_extent_type(buf, fi) ==
2546 BTRFS_FILE_EXTENT_INLINE)
2547 continue;
2548 disk_bytenr = btrfs_file_extent_disk_bytenr(buf, fi);
2549 if (disk_bytenr == 0)
2550 continue;
2551
2552 info->bytenr = disk_bytenr;
2553 info->num_bytes =
2554 btrfs_file_extent_disk_num_bytes(buf, fi);
2555 info->objectid = key.objectid;
2556 info->offset = key.offset;
2557 info++;
2558 }
2559
2560 ret = btrfs_add_leaf_ref(root, ref, shared);
2561 if (ret == -EEXIST && shared) {
2562 struct btrfs_leaf_ref *old;
2563 old = btrfs_lookup_leaf_ref(root, ref->bytenr);
2564 BUG_ON(!old);
2565 btrfs_remove_leaf_ref(root, old);
2566 btrfs_free_leaf_ref(root, old);
2567 ret = btrfs_add_leaf_ref(root, ref, shared);
2568 }
2569 WARN_ON(ret);
2570 btrfs_free_leaf_ref(root, ref);
2571 }
2572 out:
2573 return ret;
2574 }
2575
2576 /* when a block goes through cow, we update the reference counts of
2577 * everything that block points to. The internal pointers of the block
2578 * can be in just about any order, and it is likely to have clusters of
2579 * things that are close together and clusters of things that are not.
2580 *
2581 * To help reduce the seeks that come with updating all of these reference
2582 * counts, sort them by byte number before actual updates are done.
2583 *
2584 * struct refsort is used to match byte number to slot in the btree block.
2585 * we sort based on the byte number and then use the slot to actually
2586 * find the item.
2587 *
2588 * struct refsort is smaller than strcut btrfs_item and smaller than
2589 * struct btrfs_key_ptr. Since we're currently limited to the page size
2590 * for a btree block, there's no way for a kmalloc of refsorts for a
2591 * single node to be bigger than a page.
2592 */
2593 struct refsort {
2594 u64 bytenr;
2595 u32 slot;
2596 };
2597
2598 /*
2599 * for passing into sort()
2600 */
2601 static int refsort_cmp(const void *a_void, const void *b_void)
2602 {
2603 const struct refsort *a = a_void;
2604 const struct refsort *b = b_void;
2605
2606 if (a->bytenr < b->bytenr)
2607 return -1;
2608 if (a->bytenr > b->bytenr)
2609 return 1;
2610 return 0;
2611 }
2612 #endif
2613
2614 static int __btrfs_mod_ref(struct btrfs_trans_handle *trans,
2615 struct btrfs_root *root,
2616 struct extent_buffer *buf,
2617 int full_backref, int inc)
2618 {
2619 u64 bytenr;
2620 u64 num_bytes;
2621 u64 parent;
2622 u64 ref_root;
2623 u32 nritems;
2624 struct btrfs_key key;
2625 struct btrfs_file_extent_item *fi;
2626 int i;
2627 int level;
2628 int ret = 0;
2629 int (*process_func)(struct btrfs_trans_handle *, struct btrfs_root *,
2630 u64, u64, u64, u64, u64, u64);
2631
2632 ref_root = btrfs_header_owner(buf);
2633 nritems = btrfs_header_nritems(buf);
2634 level = btrfs_header_level(buf);
2635
2636 if (!root->ref_cows && level == 0)
2637 return 0;
2638
2639 if (inc)
2640 process_func = btrfs_inc_extent_ref;
2641 else
2642 process_func = btrfs_free_extent;
2643
2644 if (full_backref)
2645 parent = buf->start;
2646 else
2647 parent = 0;
2648
2649 for (i = 0; i < nritems; i++) {
2650 if (level == 0) {
2651 btrfs_item_key_to_cpu(buf, &key, i);
2652 if (btrfs_key_type(&key) != BTRFS_EXTENT_DATA_KEY)
2653 continue;
2654 fi = btrfs_item_ptr(buf, i,
2655 struct btrfs_file_extent_item);
2656 if (btrfs_file_extent_type(buf, fi) ==
2657 BTRFS_FILE_EXTENT_INLINE)
2658 continue;
2659 bytenr = btrfs_file_extent_disk_bytenr(buf, fi);
2660 if (bytenr == 0)
2661 continue;
2662
2663 num_bytes = btrfs_file_extent_disk_num_bytes(buf, fi);
2664 key.offset -= btrfs_file_extent_offset(buf, fi);
2665 ret = process_func(trans, root, bytenr, num_bytes,
2666 parent, ref_root, key.objectid,
2667 key.offset);
2668 if (ret)
2669 goto fail;
2670 } else {
2671 bytenr = btrfs_node_blockptr(buf, i);
2672 num_bytes = btrfs_level_size(root, level - 1);
2673 ret = process_func(trans, root, bytenr, num_bytes,
2674 parent, ref_root, level - 1, 0);
2675 if (ret)
2676 goto fail;
2677 }
2678 }
2679 return 0;
2680 fail:
2681 BUG();
2682 return ret;
2683 }
2684
2685 int btrfs_inc_ref(struct btrfs_trans_handle *trans, struct btrfs_root *root,
2686 struct extent_buffer *buf, int full_backref)
2687 {
2688 return __btrfs_mod_ref(trans, root, buf, full_backref, 1);
2689 }
2690
2691 int btrfs_dec_ref(struct btrfs_trans_handle *trans, struct btrfs_root *root,
2692 struct extent_buffer *buf, int full_backref)
2693 {
2694 return __btrfs_mod_ref(trans, root, buf, full_backref, 0);
2695 }
2696
2697 static int write_one_cache_group(struct btrfs_trans_handle *trans,
2698 struct btrfs_root *root,
2699 struct btrfs_path *path,
2700 struct btrfs_block_group_cache *cache)
2701 {
2702 int ret;
2703 struct btrfs_root *extent_root = root->fs_info->extent_root;
2704 unsigned long bi;
2705 struct extent_buffer *leaf;
2706
2707 ret = btrfs_search_slot(trans, extent_root, &cache->key, path, 0, 1);
2708 if (ret < 0)
2709 goto fail;
2710 BUG_ON(ret);
2711
2712 leaf = path->nodes[0];
2713 bi = btrfs_item_ptr_offset(leaf, path->slots[0]);
2714 write_extent_buffer(leaf, &cache->item, bi, sizeof(cache->item));
2715 btrfs_mark_buffer_dirty(leaf);
2716 btrfs_release_path(extent_root, path);
2717 fail:
2718 if (ret)
2719 return ret;
2720 return 0;
2721
2722 }
2723
2724 static struct btrfs_block_group_cache *
2725 next_block_group(struct btrfs_root *root,
2726 struct btrfs_block_group_cache *cache)
2727 {
2728 struct rb_node *node;
2729 spin_lock(&root->fs_info->block_group_cache_lock);
2730 node = rb_next(&cache->cache_node);
2731 btrfs_put_block_group(cache);
2732 if (node) {
2733 cache = rb_entry(node, struct btrfs_block_group_cache,
2734 cache_node);
2735 btrfs_get_block_group(cache);
2736 } else
2737 cache = NULL;
2738 spin_unlock(&root->fs_info->block_group_cache_lock);
2739 return cache;
2740 }
2741
2742 static int cache_save_setup(struct btrfs_block_group_cache *block_group,
2743 struct btrfs_trans_handle *trans,
2744 struct btrfs_path *path)
2745 {
2746 struct btrfs_root *root = block_group->fs_info->tree_root;
2747 struct inode *inode = NULL;
2748 u64 alloc_hint = 0;
2749 int dcs = BTRFS_DC_ERROR;
2750 int num_pages = 0;
2751 int retries = 0;
2752 int ret = 0;
2753
2754 /*
2755 * If this block group is smaller than 100 megs don't bother caching the
2756 * block group.
2757 */
2758 if (block_group->key.offset < (100 * 1024 * 1024)) {
2759 spin_lock(&block_group->lock);
2760 block_group->disk_cache_state = BTRFS_DC_WRITTEN;
2761 spin_unlock(&block_group->lock);
2762 return 0;
2763 }
2764
2765 again:
2766 inode = lookup_free_space_inode(root, block_group, path);
2767 if (IS_ERR(inode) && PTR_ERR(inode) != -ENOENT) {
2768 ret = PTR_ERR(inode);
2769 btrfs_release_path(root, path);
2770 goto out;
2771 }
2772
2773 if (IS_ERR(inode)) {
2774 BUG_ON(retries);
2775 retries++;
2776
2777 if (block_group->ro)
2778 goto out_free;
2779
2780 ret = create_free_space_inode(root, trans, block_group, path);
2781 if (ret)
2782 goto out_free;
2783 goto again;
2784 }
2785
2786 /*
2787 * We want to set the generation to 0, that way if anything goes wrong
2788 * from here on out we know not to trust this cache when we load up next
2789 * time.
2790 */
2791 BTRFS_I(inode)->generation = 0;
2792 ret = btrfs_update_inode(trans, root, inode);
2793 WARN_ON(ret);
2794
2795 if (i_size_read(inode) > 0) {
2796 ret = btrfs_truncate_free_space_cache(root, trans, path,
2797 inode);
2798 if (ret)
2799 goto out_put;
2800 }
2801
2802 spin_lock(&block_group->lock);
2803 if (block_group->cached != BTRFS_CACHE_FINISHED) {
2804 /* We're not cached, don't bother trying to write stuff out */
2805 dcs = BTRFS_DC_WRITTEN;
2806 spin_unlock(&block_group->lock);
2807 goto out_put;
2808 }
2809 spin_unlock(&block_group->lock);
2810
2811 num_pages = (int)div64_u64(block_group->key.offset, 1024 * 1024 * 1024);
2812 if (!num_pages)
2813 num_pages = 1;
2814
2815 /*
2816 * Just to make absolutely sure we have enough space, we're going to
2817 * preallocate 12 pages worth of space for each block group. In
2818 * practice we ought to use at most 8, but we need extra space so we can
2819 * add our header and have a terminator between the extents and the
2820 * bitmaps.
2821 */
2822 num_pages *= 16;
2823 num_pages *= PAGE_CACHE_SIZE;
2824
2825 ret = btrfs_check_data_free_space(inode, num_pages);
2826 if (ret)
2827 goto out_put;
2828
2829 ret = btrfs_prealloc_file_range_trans(inode, trans, 0, 0, num_pages,
2830 num_pages, num_pages,
2831 &alloc_hint);
2832 if (!ret)
2833 dcs = BTRFS_DC_SETUP;
2834 btrfs_free_reserved_data_space(inode, num_pages);
2835 out_put:
2836 iput(inode);
2837 out_free:
2838 btrfs_release_path(root, path);
2839 out:
2840 spin_lock(&block_group->lock);
2841 block_group->disk_cache_state = dcs;
2842 spin_unlock(&block_group->lock);
2843
2844 return ret;
2845 }
2846
2847 int btrfs_write_dirty_block_groups(struct btrfs_trans_handle *trans,
2848 struct btrfs_root *root)
2849 {
2850 struct btrfs_block_group_cache *cache;
2851 int err = 0;
2852 struct btrfs_path *path;
2853 u64 last = 0;
2854
2855 path = btrfs_alloc_path();
2856 if (!path)
2857 return -ENOMEM;
2858
2859 again:
2860 while (1) {
2861 cache = btrfs_lookup_first_block_group(root->fs_info, last);
2862 while (cache) {
2863 if (cache->disk_cache_state == BTRFS_DC_CLEAR)
2864 break;
2865 cache = next_block_group(root, cache);
2866 }
2867 if (!cache) {
2868 if (last == 0)
2869 break;
2870 last = 0;
2871 continue;
2872 }
2873 err = cache_save_setup(cache, trans, path);
2874 last = cache->key.objectid + cache->key.offset;
2875 btrfs_put_block_group(cache);
2876 }
2877
2878 while (1) {
2879 if (last == 0) {
2880 err = btrfs_run_delayed_refs(trans, root,
2881 (unsigned long)-1);
2882 BUG_ON(err);
2883 }
2884
2885 cache = btrfs_lookup_first_block_group(root->fs_info, last);
2886 while (cache) {
2887 if (cache->disk_cache_state == BTRFS_DC_CLEAR) {
2888 btrfs_put_block_group(cache);
2889 goto again;
2890 }
2891
2892 if (cache->dirty)
2893 break;
2894 cache = next_block_group(root, cache);
2895 }
2896 if (!cache) {
2897 if (last == 0)
2898 break;
2899 last = 0;
2900 continue;
2901 }
2902
2903 if (cache->disk_cache_state == BTRFS_DC_SETUP)
2904 cache->disk_cache_state = BTRFS_DC_NEED_WRITE;
2905 cache->dirty = 0;
2906 last = cache->key.objectid + cache->key.offset;
2907
2908 err = write_one_cache_group(trans, root, path, cache);
2909 BUG_ON(err);
2910 btrfs_put_block_group(cache);
2911 }
2912
2913 while (1) {
2914 /*
2915 * I don't think this is needed since we're just marking our
2916 * preallocated extent as written, but just in case it can't
2917 * hurt.
2918 */
2919 if (last == 0) {
2920 err = btrfs_run_delayed_refs(trans, root,
2921 (unsigned long)-1);
2922 BUG_ON(err);
2923 }
2924
2925 cache = btrfs_lookup_first_block_group(root->fs_info, last);
2926 while (cache) {
2927 /*
2928 * Really this shouldn't happen, but it could if we
2929 * couldn't write the entire preallocated extent and
2930 * splitting the extent resulted in a new block.
2931 */
2932 if (cache->dirty) {
2933 btrfs_put_block_group(cache);
2934 goto again;
2935 }
2936 if (cache->disk_cache_state == BTRFS_DC_NEED_WRITE)
2937 break;
2938 cache = next_block_group(root, cache);
2939 }
2940 if (!cache) {
2941 if (last == 0)
2942 break;
2943 last = 0;
2944 continue;
2945 }
2946
2947 btrfs_write_out_cache(root, trans, cache, path);
2948
2949 /*
2950 * If we didn't have an error then the cache state is still
2951 * NEED_WRITE, so we can set it to WRITTEN.
2952 */
2953 if (cache->disk_cache_state == BTRFS_DC_NEED_WRITE)
2954 cache->disk_cache_state = BTRFS_DC_WRITTEN;
2955 last = cache->key.objectid + cache->key.offset;
2956 btrfs_put_block_group(cache);
2957 }
2958
2959 btrfs_free_path(path);
2960 return 0;
2961 }
2962
2963 int btrfs_extent_readonly(struct btrfs_root *root, u64 bytenr)
2964 {
2965 struct btrfs_block_group_cache *block_group;
2966 int readonly = 0;
2967
2968 block_group = btrfs_lookup_block_group(root->fs_info, bytenr);
2969 if (!block_group || block_group->ro)
2970 readonly = 1;
2971 if (block_group)
2972 btrfs_put_block_group(block_group);
2973 return readonly;
2974 }
2975
2976 static int update_space_info(struct btrfs_fs_info *info, u64 flags,
2977 u64 total_bytes, u64 bytes_used,
2978 struct btrfs_space_info **space_info)
2979 {
2980 struct btrfs_space_info *found;
2981 int i;
2982 int factor;
2983
2984 if (flags & (BTRFS_BLOCK_GROUP_DUP | BTRFS_BLOCK_GROUP_RAID1 |
2985 BTRFS_BLOCK_GROUP_RAID10))
2986 factor = 2;
2987 else
2988 factor = 1;
2989
2990 found = __find_space_info(info, flags);
2991 if (found) {
2992 spin_lock(&found->lock);
2993 found->total_bytes += total_bytes;
2994 found->disk_total += total_bytes * factor;
2995 found->bytes_used += bytes_used;
2996 found->disk_used += bytes_used * factor;
2997 found->full = 0;
2998 spin_unlock(&found->lock);
2999 *space_info = found;
3000 return 0;
3001 }
3002 found = kzalloc(sizeof(*found), GFP_NOFS);
3003 if (!found)
3004 return -ENOMEM;
3005
3006 for (i = 0; i < BTRFS_NR_RAID_TYPES; i++)
3007 INIT_LIST_HEAD(&found->block_groups[i]);
3008 init_rwsem(&found->groups_sem);
3009 spin_lock_init(&found->lock);
3010 found->flags = flags & (BTRFS_BLOCK_GROUP_DATA |
3011 BTRFS_BLOCK_GROUP_SYSTEM |
3012 BTRFS_BLOCK_GROUP_METADATA);
3013 found->total_bytes = total_bytes;
3014 found->disk_total = total_bytes * factor;
3015 found->bytes_used = bytes_used;
3016 found->disk_used = bytes_used * factor;
3017 found->bytes_pinned = 0;
3018 found->bytes_reserved = 0;
3019 found->bytes_readonly = 0;
3020 found->bytes_may_use = 0;
3021 found->full = 0;
3022 found->force_alloc = 0;
3023 *space_info = found;
3024 list_add_rcu(&found->list, &info->space_info);
3025 atomic_set(&found->caching_threads, 0);
3026 return 0;
3027 }
3028
3029 static void set_avail_alloc_bits(struct btrfs_fs_info *fs_info, u64 flags)
3030 {
3031 u64 extra_flags = flags & (BTRFS_BLOCK_GROUP_RAID0 |
3032 BTRFS_BLOCK_GROUP_RAID1 |
3033 BTRFS_BLOCK_GROUP_RAID10 |
3034 BTRFS_BLOCK_GROUP_DUP);
3035 if (extra_flags) {
3036 if (flags & BTRFS_BLOCK_GROUP_DATA)
3037 fs_info->avail_data_alloc_bits |= extra_flags;
3038 if (flags & BTRFS_BLOCK_GROUP_METADATA)
3039 fs_info->avail_metadata_alloc_bits |= extra_flags;
3040 if (flags & BTRFS_BLOCK_GROUP_SYSTEM)
3041 fs_info->avail_system_alloc_bits |= extra_flags;
3042 }
3043 }
3044
3045 u64 btrfs_reduce_alloc_profile(struct btrfs_root *root, u64 flags)
3046 {
3047 /*
3048 * we add in the count of missing devices because we want
3049 * to make sure that any RAID levels on a degraded FS
3050 * continue to be honored.
3051 */
3052 u64 num_devices = root->fs_info->fs_devices->rw_devices +
3053 root->fs_info->fs_devices->missing_devices;
3054
3055 if (num_devices == 1)
3056 flags &= ~(BTRFS_BLOCK_GROUP_RAID1 | BTRFS_BLOCK_GROUP_RAID0);
3057 if (num_devices < 4)
3058 flags &= ~BTRFS_BLOCK_GROUP_RAID10;
3059
3060 if ((flags & BTRFS_BLOCK_GROUP_DUP) &&
3061 (flags & (BTRFS_BLOCK_GROUP_RAID1 |
3062 BTRFS_BLOCK_GROUP_RAID10))) {
3063 flags &= ~BTRFS_BLOCK_GROUP_DUP;
3064 }
3065
3066 if ((flags & BTRFS_BLOCK_GROUP_RAID1) &&
3067 (flags & BTRFS_BLOCK_GROUP_RAID10)) {
3068 flags &= ~BTRFS_BLOCK_GROUP_RAID1;
3069 }
3070
3071 if ((flags & BTRFS_BLOCK_GROUP_RAID0) &&
3072 ((flags & BTRFS_BLOCK_GROUP_RAID1) |
3073 (flags & BTRFS_BLOCK_GROUP_RAID10) |
3074 (flags & BTRFS_BLOCK_GROUP_DUP)))
3075 flags &= ~BTRFS_BLOCK_GROUP_RAID0;
3076 return flags;
3077 }
3078
3079 static u64 get_alloc_profile(struct btrfs_root *root, u64 flags)
3080 {
3081 if (flags & BTRFS_BLOCK_GROUP_DATA)
3082 flags |= root->fs_info->avail_data_alloc_bits &
3083 root->fs_info->data_alloc_profile;
3084 else if (flags & BTRFS_BLOCK_GROUP_SYSTEM)
3085 flags |= root->fs_info->avail_system_alloc_bits &
3086 root->fs_info->system_alloc_profile;
3087 else if (flags & BTRFS_BLOCK_GROUP_METADATA)
3088 flags |= root->fs_info->avail_metadata_alloc_bits &
3089 root->fs_info->metadata_alloc_profile;
3090 return btrfs_reduce_alloc_profile(root, flags);
3091 }
3092
3093 u64 btrfs_get_alloc_profile(struct btrfs_root *root, int data)
3094 {
3095 u64 flags;
3096
3097 if (data)
3098 flags = BTRFS_BLOCK_GROUP_DATA;
3099 else if (root == root->fs_info->chunk_root)
3100 flags = BTRFS_BLOCK_GROUP_SYSTEM;
3101 else
3102 flags = BTRFS_BLOCK_GROUP_METADATA;
3103
3104 return get_alloc_profile(root, flags);
3105 }
3106
3107 void btrfs_set_inode_space_info(struct btrfs_root *root, struct inode *inode)
3108 {
3109 BTRFS_I(inode)->space_info = __find_space_info(root->fs_info,
3110 BTRFS_BLOCK_GROUP_DATA);
3111 }
3112
3113 /*
3114 * This will check the space that the inode allocates from to make sure we have
3115 * enough space for bytes.
3116 */
3117 int btrfs_check_data_free_space(struct inode *inode, u64 bytes)
3118 {
3119 struct btrfs_space_info *data_sinfo;
3120 struct btrfs_root *root = BTRFS_I(inode)->root;
3121 u64 used;
3122 int ret = 0, committed = 0, alloc_chunk = 1;
3123
3124 /* make sure bytes are sectorsize aligned */
3125 bytes = (bytes + root->sectorsize - 1) & ~((u64)root->sectorsize - 1);
3126
3127 if (root == root->fs_info->tree_root) {
3128 alloc_chunk = 0;
3129 committed = 1;
3130 }
3131
3132 data_sinfo = BTRFS_I(inode)->space_info;
3133 if (!data_sinfo)
3134 goto alloc;
3135
3136 again:
3137 /* make sure we have enough space to handle the data first */
3138 spin_lock(&data_sinfo->lock);
3139 used = data_sinfo->bytes_used + data_sinfo->bytes_reserved +
3140 data_sinfo->bytes_pinned + data_sinfo->bytes_readonly +
3141 data_sinfo->bytes_may_use;
3142
3143 if (used + bytes > data_sinfo->total_bytes) {
3144 struct btrfs_trans_handle *trans;
3145
3146 /*
3147 * if we don't have enough free bytes in this space then we need
3148 * to alloc a new chunk.
3149 */
3150 if (!data_sinfo->full && alloc_chunk) {
3151 u64 alloc_target;
3152
3153 data_sinfo->force_alloc = 1;
3154 spin_unlock(&data_sinfo->lock);
3155 alloc:
3156 alloc_target = btrfs_get_alloc_profile(root, 1);
3157 trans = btrfs_join_transaction(root, 1);
3158 if (IS_ERR(trans))
3159 return PTR_ERR(trans);
3160
3161 ret = do_chunk_alloc(trans, root->fs_info->extent_root,
3162 bytes + 2 * 1024 * 1024,
3163 alloc_target, 0);
3164 btrfs_end_transaction(trans, root);
3165 if (ret < 0) {
3166 if (ret != -ENOSPC)
3167 return ret;
3168 else
3169 goto commit_trans;
3170 }
3171
3172 if (!data_sinfo) {
3173 btrfs_set_inode_space_info(root, inode);
3174 data_sinfo = BTRFS_I(inode)->space_info;
3175 }
3176 goto again;
3177 }
3178 spin_unlock(&data_sinfo->lock);
3179
3180 /* commit the current transaction and try again */
3181 commit_trans:
3182 if (!committed && !root->fs_info->open_ioctl_trans) {
3183 committed = 1;
3184 trans = btrfs_join_transaction(root, 1);
3185 if (IS_ERR(trans))
3186 return PTR_ERR(trans);
3187 ret = btrfs_commit_transaction(trans, root);
3188 if (ret)
3189 return ret;
3190 goto again;
3191 }
3192
3193 #if 0 /* I hope we never need this code again, just in case */
3194 printk(KERN_ERR "no space left, need %llu, %llu bytes_used, "
3195 "%llu bytes_reserved, " "%llu bytes_pinned, "
3196 "%llu bytes_readonly, %llu may use %llu total\n",
3197 (unsigned long long)bytes,
3198 (unsigned long long)data_sinfo->bytes_used,
3199 (unsigned long long)data_sinfo->bytes_reserved,
3200 (unsigned long long)data_sinfo->bytes_pinned,
3201 (unsigned long long)data_sinfo->bytes_readonly,
3202 (unsigned long long)data_sinfo->bytes_may_use,
3203 (unsigned long long)data_sinfo->total_bytes);
3204 #endif
3205 return -ENOSPC;
3206 }
3207 data_sinfo->bytes_may_use += bytes;
3208 BTRFS_I(inode)->reserved_bytes += bytes;
3209 spin_unlock(&data_sinfo->lock);
3210
3211 return 0;
3212 }
3213
3214 /*
3215 * called when we are clearing an delalloc extent from the
3216 * inode's io_tree or there was an error for whatever reason
3217 * after calling btrfs_check_data_free_space
3218 */
3219 void btrfs_free_reserved_data_space(struct inode *inode, u64 bytes)
3220 {
3221 struct btrfs_root *root = BTRFS_I(inode)->root;
3222 struct btrfs_space_info *data_sinfo;
3223
3224 /* make sure bytes are sectorsize aligned */
3225 bytes = (bytes + root->sectorsize - 1) & ~((u64)root->sectorsize - 1);
3226
3227 data_sinfo = BTRFS_I(inode)->space_info;
3228 spin_lock(&data_sinfo->lock);
3229 data_sinfo->bytes_may_use -= bytes;
3230 BTRFS_I(inode)->reserved_bytes -= bytes;
3231 spin_unlock(&data_sinfo->lock);
3232 }
3233
3234 static void force_metadata_allocation(struct btrfs_fs_info *info)
3235 {
3236 struct list_head *head = &info->space_info;
3237 struct btrfs_space_info *found;
3238
3239 rcu_read_lock();
3240 list_for_each_entry_rcu(found, head, list) {
3241 if (found->flags & BTRFS_BLOCK_GROUP_METADATA)
3242 found->force_alloc = 1;
3243 }
3244 rcu_read_unlock();
3245 }
3246
3247 static int should_alloc_chunk(struct btrfs_root *root,
3248 struct btrfs_space_info *sinfo, u64 alloc_bytes)
3249 {
3250 u64 num_bytes = sinfo->total_bytes - sinfo->bytes_readonly;
3251 u64 thresh;
3252
3253 if (sinfo->bytes_used + sinfo->bytes_reserved +
3254 alloc_bytes + 256 * 1024 * 1024 < num_bytes)
3255 return 0;
3256
3257 if (sinfo->bytes_used + sinfo->bytes_reserved +
3258 alloc_bytes < div_factor(num_bytes, 8))
3259 return 0;
3260
3261 thresh = btrfs_super_total_bytes(&root->fs_info->super_copy);
3262 thresh = max_t(u64, 256 * 1024 * 1024, div_factor_fine(thresh, 5));
3263
3264 if (num_bytes > thresh && sinfo->bytes_used < div_factor(num_bytes, 3))
3265 return 0;
3266
3267 return 1;
3268 }
3269
3270 static int do_chunk_alloc(struct btrfs_trans_handle *trans,
3271 struct btrfs_root *extent_root, u64 alloc_bytes,
3272 u64 flags, int force)
3273 {
3274 struct btrfs_space_info *space_info;
3275 struct btrfs_fs_info *fs_info = extent_root->fs_info;
3276 int ret = 0;
3277
3278 mutex_lock(&fs_info->chunk_mutex);
3279
3280 flags = btrfs_reduce_alloc_profile(extent_root, flags);
3281
3282 space_info = __find_space_info(extent_root->fs_info, flags);
3283 if (!space_info) {
3284 ret = update_space_info(extent_root->fs_info, flags,
3285 0, 0, &space_info);
3286 BUG_ON(ret);
3287 }
3288 BUG_ON(!space_info);
3289
3290 spin_lock(&space_info->lock);
3291 if (space_info->force_alloc)
3292 force = 1;
3293 if (space_info->full) {
3294 spin_unlock(&space_info->lock);
3295 goto out;
3296 }
3297
3298 if (!force && !should_alloc_chunk(extent_root, space_info,
3299 alloc_bytes)) {
3300 spin_unlock(&space_info->lock);
3301 goto out;
3302 }
3303 spin_unlock(&space_info->lock);
3304
3305 /*
3306 * If we have mixed data/metadata chunks we want to make sure we keep
3307 * allocating mixed chunks instead of individual chunks.
3308 */
3309 if (btrfs_mixed_space_info(space_info))
3310 flags |= (BTRFS_BLOCK_GROUP_DATA | BTRFS_BLOCK_GROUP_METADATA);
3311
3312 /*
3313 * if we're doing a data chunk, go ahead and make sure that
3314 * we keep a reasonable number of metadata chunks allocated in the
3315 * FS as well.
3316 */
3317 if (flags & BTRFS_BLOCK_GROUP_DATA && fs_info->metadata_ratio) {
3318 fs_info->data_chunk_allocations++;
3319 if (!(fs_info->data_chunk_allocations %
3320 fs_info->metadata_ratio))
3321 force_metadata_allocation(fs_info);
3322 }
3323
3324 ret = btrfs_alloc_chunk(trans, extent_root, flags);
3325 spin_lock(&space_info->lock);
3326 if (ret)
3327 space_info->full = 1;
3328 else
3329 ret = 1;
3330 space_info->force_alloc = 0;
3331 spin_unlock(&space_info->lock);
3332 out:
3333 mutex_unlock(&extent_root->fs_info->chunk_mutex);
3334 return ret;
3335 }
3336
3337 /*
3338 * shrink metadata reservation for delalloc
3339 */
3340 static int shrink_delalloc(struct btrfs_trans_handle *trans,
3341 struct btrfs_root *root, u64 to_reclaim, int sync)
3342 {
3343 struct btrfs_block_rsv *block_rsv;
3344 struct btrfs_space_info *space_info;
3345 u64 reserved;
3346 u64 max_reclaim;
3347 u64 reclaimed = 0;
3348 long time_left;
3349 int nr_pages = (2 * 1024 * 1024) >> PAGE_CACHE_SHIFT;
3350 int loops = 0;
3351 unsigned long progress;
3352
3353 block_rsv = &root->fs_info->delalloc_block_rsv;
3354 space_info = block_rsv->space_info;
3355
3356 smp_mb();
3357 reserved = space_info->bytes_reserved;
3358 progress = space_info->reservation_progress;
3359
3360 if (reserved == 0)
3361 return 0;
3362
3363 max_reclaim = min(reserved, to_reclaim);
3364
3365 while (loops < 1024) {
3366 /* have the flusher threads jump in and do some IO */
3367 smp_mb();
3368 nr_pages = min_t(unsigned long, nr_pages,
3369 root->fs_info->delalloc_bytes >> PAGE_CACHE_SHIFT);
3370 writeback_inodes_sb_nr_if_idle(root->fs_info->sb, nr_pages);
3371
3372 spin_lock(&space_info->lock);
3373 if (reserved > space_info->bytes_reserved)
3374 reclaimed += reserved - space_info->bytes_reserved;
3375 reserved = space_info->bytes_reserved;
3376 spin_unlock(&space_info->lock);
3377
3378 loops++;
3379
3380 if (reserved == 0 || reclaimed >= max_reclaim)
3381 break;
3382
3383 if (trans && trans->transaction->blocked)
3384 return -EAGAIN;
3385
3386 time_left = schedule_timeout_interruptible(1);
3387
3388 /* We were interrupted, exit */
3389 if (time_left)
3390 break;
3391
3392 /* we've kicked the IO a few times, if anything has been freed,
3393 * exit. There is no sense in looping here for a long time
3394 * when we really need to commit the transaction, or there are
3395 * just too many writers without enough free space
3396 */
3397
3398 if (loops > 3) {
3399 smp_mb();
3400 if (progress != space_info->reservation_progress)
3401 break;
3402 }
3403
3404 }
3405 return reclaimed >= to_reclaim;
3406 }
3407
3408 /*
3409 * Retries tells us how many times we've called reserve_metadata_bytes. The
3410 * idea is if this is the first call (retries == 0) then we will add to our
3411 * reserved count if we can't make the allocation in order to hold our place
3412 * while we go and try and free up space. That way for retries > 1 we don't try
3413 * and add space, we just check to see if the amount of unused space is >= the
3414 * total space, meaning that our reservation is valid.
3415 *
3416 * However if we don't intend to retry this reservation, pass -1 as retries so
3417 * that it short circuits this logic.
3418 */
3419 static int reserve_metadata_bytes(struct btrfs_trans_handle *trans,
3420 struct btrfs_root *root,
3421 struct btrfs_block_rsv *block_rsv,
3422 u64 orig_bytes, int flush)
3423 {
3424 struct btrfs_space_info *space_info = block_rsv->space_info;
3425 u64 unused;
3426 u64 num_bytes = orig_bytes;
3427 int retries = 0;
3428 int ret = 0;
3429 bool reserved = false;
3430 bool committed = false;
3431
3432 again:
3433 ret = -ENOSPC;
3434 if (reserved)
3435 num_bytes = 0;
3436
3437 spin_lock(&space_info->lock);
3438 unused = space_info->bytes_used + space_info->bytes_reserved +
3439 space_info->bytes_pinned + space_info->bytes_readonly +
3440 space_info->bytes_may_use;
3441
3442 /*
3443 * The idea here is that we've not already over-reserved the block group
3444 * then we can go ahead and save our reservation first and then start
3445 * flushing if we need to. Otherwise if we've already overcommitted
3446 * lets start flushing stuff first and then come back and try to make
3447 * our reservation.
3448 */
3449 if (unused <= space_info->total_bytes) {
3450 unused = space_info->total_bytes - unused;
3451 if (unused >= num_bytes) {
3452 if (!reserved)
3453 space_info->bytes_reserved += orig_bytes;
3454 ret = 0;
3455 } else {
3456 /*
3457 * Ok set num_bytes to orig_bytes since we aren't
3458 * overocmmitted, this way we only try and reclaim what
3459 * we need.
3460 */
3461 num_bytes = orig_bytes;
3462 }
3463 } else {
3464 /*
3465 * Ok we're over committed, set num_bytes to the overcommitted
3466 * amount plus the amount of bytes that we need for this
3467 * reservation.
3468 */
3469 num_bytes = unused - space_info->total_bytes +
3470 (orig_bytes * (retries + 1));
3471 }
3472
3473 /*
3474 * Couldn't make our reservation, save our place so while we're trying
3475 * to reclaim space we can actually use it instead of somebody else
3476 * stealing it from us.
3477 */
3478 if (ret && !reserved) {
3479 space_info->bytes_reserved += orig_bytes;
3480 reserved = true;
3481 }
3482
3483 spin_unlock(&space_info->lock);
3484
3485 if (!ret)
3486 return 0;
3487
3488 if (!flush)
3489 goto out;
3490
3491 /*
3492 * We do synchronous shrinking since we don't actually unreserve
3493 * metadata until after the IO is completed.
3494 */
3495 ret = shrink_delalloc(trans, root, num_bytes, 1);
3496 if (ret > 0)
3497 return 0;
3498 else if (ret < 0)
3499 goto out;
3500
3501 /*
3502 * So if we were overcommitted it's possible that somebody else flushed
3503 * out enough space and we simply didn't have enough space to reclaim,
3504 * so go back around and try again.
3505 */
3506 if (retries < 2) {
3507 retries++;
3508 goto again;
3509 }
3510
3511 spin_lock(&space_info->lock);
3512 /*
3513 * Not enough space to be reclaimed, don't bother committing the
3514 * transaction.
3515 */
3516 if (space_info->bytes_pinned < orig_bytes)
3517 ret = -ENOSPC;
3518 spin_unlock(&space_info->lock);
3519 if (ret)
3520 goto out;
3521
3522 ret = -EAGAIN;
3523 if (trans || committed)
3524 goto out;
3525
3526 ret = -ENOSPC;
3527 trans = btrfs_join_transaction(root, 1);
3528 if (IS_ERR(trans))
3529 goto out;
3530 ret = btrfs_commit_transaction(trans, root);
3531 if (!ret) {
3532 trans = NULL;
3533 committed = true;
3534 goto again;
3535 }
3536
3537 out:
3538 if (reserved) {
3539 spin_lock(&space_info->lock);
3540 space_info->bytes_reserved -= orig_bytes;
3541 spin_unlock(&space_info->lock);
3542 }
3543
3544 return ret;
3545 }
3546
3547 static struct btrfs_block_rsv *get_block_rsv(struct btrfs_trans_handle *trans,
3548 struct btrfs_root *root)
3549 {
3550 struct btrfs_block_rsv *block_rsv;
3551 if (root->ref_cows)
3552 block_rsv = trans->block_rsv;
3553 else
3554 block_rsv = root->block_rsv;
3555
3556 if (!block_rsv)
3557 block_rsv = &root->fs_info->empty_block_rsv;
3558
3559 return block_rsv;
3560 }
3561
3562 static int block_rsv_use_bytes(struct btrfs_block_rsv *block_rsv,
3563 u64 num_bytes)
3564 {
3565 int ret = -ENOSPC;
3566 spin_lock(&block_rsv->lock);
3567 if (block_rsv->reserved >= num_bytes) {
3568 block_rsv->reserved -= num_bytes;
3569 if (block_rsv->reserved < block_rsv->size)
3570 block_rsv->full = 0;
3571 ret = 0;
3572 }
3573 spin_unlock(&block_rsv->lock);
3574 return ret;
3575 }
3576
3577 static void block_rsv_add_bytes(struct btrfs_block_rsv *block_rsv,
3578 u64 num_bytes, int update_size)
3579 {
3580 spin_lock(&block_rsv->lock);
3581 block_rsv->reserved += num_bytes;
3582 if (update_size)
3583 block_rsv->size += num_bytes;
3584 else if (block_rsv->reserved >= block_rsv->size)
3585 block_rsv->full = 1;
3586 spin_unlock(&block_rsv->lock);
3587 }
3588
3589 void block_rsv_release_bytes(struct btrfs_block_rsv *block_rsv,
3590 struct btrfs_block_rsv *dest, u64 num_bytes)
3591 {
3592 struct btrfs_space_info *space_info = block_rsv->space_info;
3593
3594 spin_lock(&block_rsv->lock);
3595 if (num_bytes == (u64)-1)
3596 num_bytes = block_rsv->size;
3597 block_rsv->size -= num_bytes;
3598 if (block_rsv->reserved >= block_rsv->size) {
3599 num_bytes = block_rsv->reserved - block_rsv->size;
3600 block_rsv->reserved = block_rsv->size;
3601 block_rsv->full = 1;
3602 } else {
3603 num_bytes = 0;
3604 }
3605 spin_unlock(&block_rsv->lock);
3606
3607 if (num_bytes > 0) {
3608 if (dest) {
3609 spin_lock(&dest->lock);
3610 if (!dest->full) {
3611 u64 bytes_to_add;
3612
3613 bytes_to_add = dest->size - dest->reserved;
3614 bytes_to_add = min(num_bytes, bytes_to_add);
3615 dest->reserved += bytes_to_add;
3616 if (dest->reserved >= dest->size)
3617 dest->full = 1;
3618 num_bytes -= bytes_to_add;
3619 }
3620 spin_unlock(&dest->lock);
3621 }
3622 if (num_bytes) {
3623 spin_lock(&space_info->lock);
3624 space_info->bytes_reserved -= num_bytes;
3625 space_info->reservation_progress++;
3626 spin_unlock(&space_info->lock);
3627 }
3628 }
3629 }
3630
3631 static int block_rsv_migrate_bytes(struct btrfs_block_rsv *src,
3632 struct btrfs_block_rsv *dst, u64 num_bytes)
3633 {
3634 int ret;
3635
3636 ret = block_rsv_use_bytes(src, num_bytes);
3637 if (ret)
3638 return ret;
3639
3640 block_rsv_add_bytes(dst, num_bytes, 1);
3641 return 0;
3642 }
3643
3644 void btrfs_init_block_rsv(struct btrfs_block_rsv *rsv)
3645 {
3646 memset(rsv, 0, sizeof(*rsv));
3647 spin_lock_init(&rsv->lock);
3648 atomic_set(&rsv->usage, 1);
3649 rsv->priority = 6;
3650 INIT_LIST_HEAD(&rsv->list);
3651 }
3652
3653 struct btrfs_block_rsv *btrfs_alloc_block_rsv(struct btrfs_root *root)
3654 {
3655 struct btrfs_block_rsv *block_rsv;
3656 struct btrfs_fs_info *fs_info = root->fs_info;
3657
3658 block_rsv = kmalloc(sizeof(*block_rsv), GFP_NOFS);
3659 if (!block_rsv)
3660 return NULL;
3661
3662 btrfs_init_block_rsv(block_rsv);
3663 block_rsv->space_info = __find_space_info(fs_info,
3664 BTRFS_BLOCK_GROUP_METADATA);
3665 return block_rsv;
3666 }
3667
3668 void btrfs_free_block_rsv(struct btrfs_root *root,
3669 struct btrfs_block_rsv *rsv)
3670 {
3671 if (rsv && atomic_dec_and_test(&rsv->usage)) {
3672 btrfs_block_rsv_release(root, rsv, (u64)-1);
3673 if (!rsv->durable)
3674 kfree(rsv);
3675 }
3676 }
3677
3678 /*
3679 * make the block_rsv struct be able to capture freed space.
3680 * the captured space will re-add to the the block_rsv struct
3681 * after transaction commit
3682 */
3683 void btrfs_add_durable_block_rsv(struct btrfs_fs_info *fs_info,
3684 struct btrfs_block_rsv *block_rsv)
3685 {
3686 block_rsv->durable = 1;
3687 mutex_lock(&fs_info->durable_block_rsv_mutex);
3688 list_add_tail(&block_rsv->list, &fs_info->durable_block_rsv_list);
3689 mutex_unlock(&fs_info->durable_block_rsv_mutex);
3690 }
3691
3692 int btrfs_block_rsv_add(struct btrfs_trans_handle *trans,
3693 struct btrfs_root *root,
3694 struct btrfs_block_rsv *block_rsv,
3695 u64 num_bytes)
3696 {
3697 int ret;
3698
3699 if (num_bytes == 0)
3700 return 0;
3701
3702 ret = reserve_metadata_bytes(trans, root, block_rsv, num_bytes, 1);
3703 if (!ret) {
3704 block_rsv_add_bytes(block_rsv, num_bytes, 1);
3705 return 0;
3706 }
3707
3708 return ret;
3709 }
3710
3711 int btrfs_block_rsv_check(struct btrfs_trans_handle *trans,
3712 struct btrfs_root *root,
3713 struct btrfs_block_rsv *block_rsv,
3714 u64 min_reserved, int min_factor)
3715 {
3716 u64 num_bytes = 0;
3717 int commit_trans = 0;
3718 int ret = -ENOSPC;
3719
3720 if (!block_rsv)
3721 return 0;
3722
3723 spin_lock(&block_rsv->lock);
3724 if (min_factor > 0)
3725 num_bytes = div_factor(block_rsv->size, min_factor);
3726 if (min_reserved > num_bytes)
3727 num_bytes = min_reserved;
3728
3729 if (block_rsv->reserved >= num_bytes) {
3730 ret = 0;
3731 } else {
3732 num_bytes -= block_rsv->reserved;
3733 if (block_rsv->durable &&
3734 block_rsv->freed[0] + block_rsv->freed[1] >= num_bytes)
3735 commit_trans = 1;
3736 }
3737 spin_unlock(&block_rsv->lock);
3738 if (!ret)
3739 return 0;
3740
3741 if (block_rsv->refill_used) {
3742 ret = reserve_metadata_bytes(trans, root, block_rsv,
3743 num_bytes, 0);
3744 if (!ret) {
3745 block_rsv_add_bytes(block_rsv, num_bytes, 0);
3746 return 0;
3747 }
3748 }
3749
3750 if (commit_trans) {
3751 if (trans)
3752 return -EAGAIN;
3753
3754 trans = btrfs_join_transaction(root, 1);
3755 BUG_ON(IS_ERR(trans));
3756 ret = btrfs_commit_transaction(trans, root);
3757 return 0;
3758 }
3759
3760 return -ENOSPC;
3761 }
3762
3763 int btrfs_block_rsv_migrate(struct btrfs_block_rsv *src_rsv,
3764 struct btrfs_block_rsv *dst_rsv,
3765 u64 num_bytes)
3766 {
3767 return block_rsv_migrate_bytes(src_rsv, dst_rsv, num_bytes);
3768 }
3769
3770 void btrfs_block_rsv_release(struct btrfs_root *root,
3771 struct btrfs_block_rsv *block_rsv,
3772 u64 num_bytes)
3773 {
3774 struct btrfs_block_rsv *global_rsv = &root->fs_info->global_block_rsv;
3775 if (global_rsv->full || global_rsv == block_rsv ||
3776 block_rsv->space_info != global_rsv->space_info)
3777 global_rsv = NULL;
3778 block_rsv_release_bytes(block_rsv, global_rsv, num_bytes);
3779 }
3780
3781 /*
3782 * helper to calculate size of global block reservation.
3783 * the desired value is sum of space used by extent tree,
3784 * checksum tree and root tree
3785 */
3786 static u64 calc_global_metadata_size(struct btrfs_fs_info *fs_info)
3787 {
3788 struct btrfs_space_info *sinfo;
3789 u64 num_bytes;
3790 u64 meta_used;
3791 u64 data_used;
3792 int csum_size = btrfs_super_csum_size(&fs_info->super_copy);
3793 #if 0
3794 /*
3795 * per tree used space accounting can be inaccuracy, so we
3796 * can't rely on it.
3797 */
3798 spin_lock(&fs_info->extent_root->accounting_lock);
3799 num_bytes = btrfs_root_used(&fs_info->extent_root->root_item);
3800 spin_unlock(&fs_info->extent_root->accounting_lock);
3801
3802 spin_lock(&fs_info->csum_root->accounting_lock);
3803 num_bytes += btrfs_root_used(&fs_info->csum_root->root_item);
3804 spin_unlock(&fs_info->csum_root->accounting_lock);
3805
3806 spin_lock(&fs_info->tree_root->accounting_lock);
3807 num_bytes += btrfs_root_used(&fs_info->tree_root->root_item);
3808 spin_unlock(&fs_info->tree_root->accounting_lock);
3809 #endif
3810 sinfo = __find_space_info(fs_info, BTRFS_BLOCK_GROUP_DATA);
3811 spin_lock(&sinfo->lock);
3812 data_used = sinfo->bytes_used;
3813 spin_unlock(&sinfo->lock);
3814
3815 sinfo = __find_space_info(fs_info, BTRFS_BLOCK_GROUP_METADATA);
3816 spin_lock(&sinfo->lock);
3817 if (sinfo->flags & BTRFS_BLOCK_GROUP_DATA)
3818 data_used = 0;
3819 meta_used = sinfo->bytes_used;
3820 spin_unlock(&sinfo->lock);
3821
3822 num_bytes = (data_used >> fs_info->sb->s_blocksize_bits) *
3823 csum_size * 2;
3824 num_bytes += div64_u64(data_used + meta_used, 50);
3825
3826 if (num_bytes * 3 > meta_used)
3827 num_bytes = div64_u64(meta_used, 3);
3828
3829 return ALIGN(num_bytes, fs_info->extent_root->leafsize << 10);
3830 }
3831
3832 static void update_global_block_rsv(struct btrfs_fs_info *fs_info)
3833 {
3834 struct btrfs_block_rsv *block_rsv = &fs_info->global_block_rsv;
3835 struct btrfs_space_info *sinfo = block_rsv->space_info;
3836 u64 num_bytes;
3837
3838 num_bytes = calc_global_metadata_size(fs_info);
3839
3840 spin_lock(&block_rsv->lock);
3841 spin_lock(&sinfo->lock);
3842
3843 block_rsv->size = num_bytes;
3844
3845 num_bytes = sinfo->bytes_used + sinfo->bytes_pinned +
3846 sinfo->bytes_reserved + sinfo->bytes_readonly +
3847 sinfo->bytes_may_use;
3848
3849 if (sinfo->total_bytes > num_bytes) {
3850 num_bytes = sinfo->total_bytes - num_bytes;
3851 block_rsv->reserved += num_bytes;
3852 sinfo->bytes_reserved += num_bytes;
3853 }
3854
3855 if (block_rsv->reserved >= block_rsv->size) {
3856 num_bytes = block_rsv->reserved - block_rsv->size;
3857 sinfo->bytes_reserved -= num_bytes;
3858 sinfo->reservation_progress++;
3859 block_rsv->reserved = block_rsv->size;
3860 block_rsv->full = 1;
3861 }
3862 #if 0
3863 printk(KERN_INFO"global block rsv size %llu reserved %llu\n",
3864 block_rsv->size, block_rsv->reserved);
3865 #endif
3866 spin_unlock(&sinfo->lock);
3867 spin_unlock(&block_rsv->lock);
3868 }
3869
3870 static void init_global_block_rsv(struct btrfs_fs_info *fs_info)
3871 {
3872 struct btrfs_space_info *space_info;
3873
3874 space_info = __find_space_info(fs_info, BTRFS_BLOCK_GROUP_SYSTEM);
3875 fs_info->chunk_block_rsv.space_info = space_info;
3876 fs_info->chunk_block_rsv.priority = 10;
3877
3878 space_info = __find_space_info(fs_info, BTRFS_BLOCK_GROUP_METADATA);
3879 fs_info->global_block_rsv.space_info = space_info;
3880 fs_info->global_block_rsv.priority = 10;
3881 fs_info->global_block_rsv.refill_used = 1;
3882 fs_info->delalloc_block_rsv.space_info = space_info;
3883 fs_info->trans_block_rsv.space_info = space_info;
3884 fs_info->empty_block_rsv.space_info = space_info;
3885 fs_info->empty_block_rsv.priority = 10;
3886
3887 fs_info->extent_root->block_rsv = &fs_info->global_block_rsv;
3888 fs_info->csum_root->block_rsv = &fs_info->global_block_rsv;
3889 fs_info->dev_root->block_rsv = &fs_info->global_block_rsv;
3890 fs_info->tree_root->block_rsv = &fs_info->global_block_rsv;
3891 fs_info->chunk_root->block_rsv = &fs_info->chunk_block_rsv;
3892
3893 btrfs_add_durable_block_rsv(fs_info, &fs_info->global_block_rsv);
3894
3895 btrfs_add_durable_block_rsv(fs_info, &fs_info->delalloc_block_rsv);
3896
3897 update_global_block_rsv(fs_info);
3898 }
3899
3900 static void release_global_block_rsv(struct btrfs_fs_info *fs_info)
3901 {
3902 block_rsv_release_bytes(&fs_info->global_block_rsv, NULL, (u64)-1);
3903 WARN_ON(fs_info->delalloc_block_rsv.size > 0);
3904 WARN_ON(fs_info->delalloc_block_rsv.reserved > 0);
3905 WARN_ON(fs_info->trans_block_rsv.size > 0);
3906 WARN_ON(fs_info->trans_block_rsv.reserved > 0);
3907 WARN_ON(fs_info->chunk_block_rsv.size > 0);
3908 WARN_ON(fs_info->chunk_block_rsv.reserved > 0);
3909 }
3910
3911 static u64 calc_trans_metadata_size(struct btrfs_root *root, int num_items)
3912 {
3913 return (root->leafsize + root->nodesize * (BTRFS_MAX_LEVEL - 1)) *
3914 3 * num_items;
3915 }
3916
3917 int btrfs_trans_reserve_metadata(struct btrfs_trans_handle *trans,
3918 struct btrfs_root *root,
3919 int num_items)
3920 {
3921 u64 num_bytes;
3922 int ret;
3923
3924 if (num_items == 0 || root->fs_info->chunk_root == root)
3925 return 0;
3926
3927 num_bytes = calc_trans_metadata_size(root, num_items);
3928 ret = btrfs_block_rsv_add(trans, root, &root->fs_info->trans_block_rsv,
3929 num_bytes);
3930 if (!ret) {
3931 trans->bytes_reserved += num_bytes;
3932 trans->block_rsv = &root->fs_info->trans_block_rsv;
3933 }
3934 return ret;
3935 }
3936
3937 void btrfs_trans_release_metadata(struct btrfs_trans_handle *trans,
3938 struct btrfs_root *root)
3939 {
3940 if (!trans->bytes_reserved)
3941 return;
3942
3943 BUG_ON(trans->block_rsv != &root->fs_info->trans_block_rsv);
3944 btrfs_block_rsv_release(root, trans->block_rsv,
3945 trans->bytes_reserved);
3946 trans->bytes_reserved = 0;
3947 }
3948
3949 int btrfs_orphan_reserve_metadata(struct btrfs_trans_handle *trans,
3950 struct inode *inode)
3951 {
3952 struct btrfs_root *root = BTRFS_I(inode)->root;
3953 struct btrfs_block_rsv *src_rsv = get_block_rsv(trans, root);
3954 struct btrfs_block_rsv *dst_rsv = root->orphan_block_rsv;
3955
3956 /*
3957 * one for deleting orphan item, one for updating inode and
3958 * two for calling btrfs_truncate_inode_items.
3959 *
3960 * btrfs_truncate_inode_items is a delete operation, it frees
3961 * more space than it uses in most cases. So two units of
3962 * metadata space should be enough for calling it many times.
3963 * If all of the metadata space is used, we can commit
3964 * transaction and use space it freed.
3965 */
3966 u64 num_bytes = calc_trans_metadata_size(root, 4);
3967 return block_rsv_migrate_bytes(src_rsv, dst_rsv, num_bytes);
3968 }
3969
3970 void btrfs_orphan_release_metadata(struct inode *inode)
3971 {
3972 struct btrfs_root *root = BTRFS_I(inode)->root;
3973 u64 num_bytes = calc_trans_metadata_size(root, 4);
3974 btrfs_block_rsv_release(root, root->orphan_block_rsv, num_bytes);
3975 }
3976
3977 int btrfs_snap_reserve_metadata(struct btrfs_trans_handle *trans,
3978 struct btrfs_pending_snapshot *pending)
3979 {
3980 struct btrfs_root *root = pending->root;
3981 struct btrfs_block_rsv *src_rsv = get_block_rsv(trans, root);
3982 struct btrfs_block_rsv *dst_rsv = &pending->block_rsv;
3983 /*
3984 * two for root back/forward refs, two for directory entries
3985 * and one for root of the snapshot.
3986 */
3987 u64 num_bytes = calc_trans_metadata_size(root, 5);
3988 dst_rsv->space_info = src_rsv->space_info;
3989 return block_rsv_migrate_bytes(src_rsv, dst_rsv, num_bytes);
3990 }
3991
3992 static u64 calc_csum_metadata_size(struct inode *inode, u64 num_bytes)
3993 {
3994 return num_bytes >>= 3;
3995 }
3996
3997 int btrfs_delalloc_reserve_metadata(struct inode *inode, u64 num_bytes)
3998 {
3999 struct btrfs_root *root = BTRFS_I(inode)->root;
4000 struct btrfs_block_rsv *block_rsv = &root->fs_info->delalloc_block_rsv;
4001 u64 to_reserve;
4002 int nr_extents;
4003 int reserved_extents;
4004 int ret;
4005
4006 if (btrfs_transaction_in_commit(root->fs_info))
4007 schedule_timeout(1);
4008
4009 num_bytes = ALIGN(num_bytes, root->sectorsize);
4010
4011 nr_extents = atomic_read(&BTRFS_I(inode)->outstanding_extents) + 1;
4012 reserved_extents = atomic_read(&BTRFS_I(inode)->reserved_extents);
4013
4014 if (nr_extents > reserved_extents) {
4015 nr_extents -= reserved_extents;
4016 to_reserve = calc_trans_metadata_size(root, nr_extents);
4017 } else {
4018 nr_extents = 0;
4019 to_reserve = 0;
4020 }
4021
4022 to_reserve += calc_csum_metadata_size(inode, num_bytes);
4023 ret = reserve_metadata_bytes(NULL, root, block_rsv, to_reserve, 1);
4024 if (ret)
4025 return ret;
4026
4027 atomic_add(nr_extents, &BTRFS_I(inode)->reserved_extents);
4028 atomic_inc(&BTRFS_I(inode)->outstanding_extents);
4029
4030 block_rsv_add_bytes(block_rsv, to_reserve, 1);
4031
4032 if (block_rsv->size > 512 * 1024 * 1024)
4033 shrink_delalloc(NULL, root, to_reserve, 0);
4034
4035 return 0;
4036 }
4037
4038 void btrfs_delalloc_release_metadata(struct inode *inode, u64 num_bytes)
4039 {
4040 struct btrfs_root *root = BTRFS_I(inode)->root;
4041 u64 to_free;
4042 int nr_extents;
4043 int reserved_extents;
4044
4045 num_bytes = ALIGN(num_bytes, root->sectorsize);
4046 atomic_dec(&BTRFS_I(inode)->outstanding_extents);
4047 WARN_ON(atomic_read(&BTRFS_I(inode)->outstanding_extents) < 0);
4048
4049 reserved_extents = atomic_read(&BTRFS_I(inode)->reserved_extents);
4050 do {
4051 int old, new;
4052
4053 nr_extents = atomic_read(&BTRFS_I(inode)->outstanding_extents);
4054 if (nr_extents >= reserved_extents) {
4055 nr_extents = 0;
4056 break;
4057 }
4058 old = reserved_extents;
4059 nr_extents = reserved_extents - nr_extents;
4060 new = reserved_extents - nr_extents;
4061 old = atomic_cmpxchg(&BTRFS_I(inode)->reserved_extents,
4062 reserved_extents, new);
4063 if (likely(old == reserved_extents))
4064 break;
4065 reserved_extents = old;
4066 } while (1);
4067
4068 to_free = calc_csum_metadata_size(inode, num_bytes);
4069 if (nr_extents > 0)
4070 to_free += calc_trans_metadata_size(root, nr_extents);
4071
4072 btrfs_block_rsv_release(root, &root->fs_info->delalloc_block_rsv,
4073 to_free);
4074 }
4075
4076 int btrfs_delalloc_reserve_space(struct inode *inode, u64 num_bytes)
4077 {
4078 int ret;
4079
4080 ret = btrfs_check_data_free_space(inode, num_bytes);
4081 if (ret)
4082 return ret;
4083
4084 ret = btrfs_delalloc_reserve_metadata(inode, num_bytes);
4085 if (ret) {
4086 btrfs_free_reserved_data_space(inode, num_bytes);
4087 return ret;
4088 }
4089
4090 return 0;
4091 }
4092
4093 void btrfs_delalloc_release_space(struct inode *inode, u64 num_bytes)
4094 {
4095 btrfs_delalloc_release_metadata(inode, num_bytes);
4096 btrfs_free_reserved_data_space(inode, num_bytes);
4097 }
4098
4099 static int update_block_group(struct btrfs_trans_handle *trans,
4100 struct btrfs_root *root,
4101 u64 bytenr, u64 num_bytes, int alloc)
4102 {
4103 struct btrfs_block_group_cache *cache = NULL;
4104 struct btrfs_fs_info *info = root->fs_info;
4105 u64 total = num_bytes;
4106 u64 old_val;
4107 u64 byte_in_group;
4108 int factor;
4109
4110 /* block accounting for super block */
4111 spin_lock(&info->delalloc_lock);
4112 old_val = btrfs_super_bytes_used(&info->super_copy);
4113 if (alloc)
4114 old_val += num_bytes;
4115 else
4116 old_val -= num_bytes;
4117 btrfs_set_super_bytes_used(&info->super_copy, old_val);
4118 spin_unlock(&info->delalloc_lock);
4119
4120 while (total) {
4121 cache = btrfs_lookup_block_group(info, bytenr);
4122 if (!cache)
4123 return -1;
4124 if (cache->flags & (BTRFS_BLOCK_GROUP_DUP |
4125 BTRFS_BLOCK_GROUP_RAID1 |
4126 BTRFS_BLOCK_GROUP_RAID10))
4127 factor = 2;
4128 else
4129 factor = 1;
4130 /*
4131 * If this block group has free space cache written out, we
4132 * need to make sure to load it if we are removing space. This
4133 * is because we need the unpinning stage to actually add the
4134 * space back to the block group, otherwise we will leak space.
4135 */
4136 if (!alloc && cache->cached == BTRFS_CACHE_NO)
4137 cache_block_group(cache, trans, NULL, 1);
4138
4139 byte_in_group = bytenr - cache->key.objectid;
4140 WARN_ON(byte_in_group > cache->key.offset);
4141
4142 spin_lock(&cache->space_info->lock);
4143 spin_lock(&cache->lock);
4144
4145 if (btrfs_super_cache_generation(&info->super_copy) != 0 &&
4146 cache->disk_cache_state < BTRFS_DC_CLEAR)
4147 cache->disk_cache_state = BTRFS_DC_CLEAR;
4148
4149 cache->dirty = 1;
4150 old_val = btrfs_block_group_used(&cache->item);
4151 num_bytes = min(total, cache->key.offset - byte_in_group);
4152 if (alloc) {
4153 old_val += num_bytes;
4154 btrfs_set_block_group_used(&cache->item, old_val);
4155 cache->reserved -= num_bytes;
4156 cache->space_info->bytes_reserved -= num_bytes;
4157 cache->space_info->reservation_progress++;
4158 cache->space_info->bytes_used += num_bytes;
4159 cache->space_info->disk_used += num_bytes * factor;
4160 spin_unlock(&cache->lock);
4161 spin_unlock(&cache->space_info->lock);
4162 } else {
4163 old_val -= num_bytes;
4164 btrfs_set_block_group_used(&cache->item, old_val);
4165 cache->pinned += num_bytes;
4166 cache->space_info->bytes_pinned += num_bytes;
4167 cache->space_info->bytes_used -= num_bytes;
4168 cache->space_info->disk_used -= num_bytes * factor;
4169 spin_unlock(&cache->lock);
4170 spin_unlock(&cache->space_info->lock);
4171
4172 set_extent_dirty(info->pinned_extents,
4173 bytenr, bytenr + num_bytes - 1,
4174 GFP_NOFS | __GFP_NOFAIL);
4175 }
4176 btrfs_put_block_group(cache);
4177 total -= num_bytes;
4178 bytenr += num_bytes;
4179 }
4180 return 0;
4181 }
4182
4183 static u64 first_logical_byte(struct btrfs_root *root, u64 search_start)
4184 {
4185 struct btrfs_block_group_cache *cache;
4186 u64 bytenr;
4187
4188 cache = btrfs_lookup_first_block_group(root->fs_info, search_start);
4189 if (!cache)
4190 return 0;
4191
4192 bytenr = cache->key.objectid;
4193 btrfs_put_block_group(cache);
4194
4195 return bytenr;
4196 }
4197
4198 static int pin_down_extent(struct btrfs_root *root,
4199 struct btrfs_block_group_cache *cache,
4200 u64 bytenr, u64 num_bytes, int reserved)
4201 {
4202 spin_lock(&cache->space_info->lock);
4203 spin_lock(&cache->lock);
4204 cache->pinned += num_bytes;
4205 cache->space_info->bytes_pinned += num_bytes;
4206 if (reserved) {
4207 cache->reserved -= num_bytes;
4208 cache->space_info->bytes_reserved -= num_bytes;
4209 cache->space_info->reservation_progress++;
4210 }
4211 spin_unlock(&cache->lock);
4212 spin_unlock(&cache->space_info->lock);
4213
4214 set_extent_dirty(root->fs_info->pinned_extents, bytenr,
4215 bytenr + num_bytes - 1, GFP_NOFS | __GFP_NOFAIL);
4216 return 0;
4217 }
4218
4219 /*
4220 * this function must be called within transaction
4221 */
4222 int btrfs_pin_extent(struct btrfs_root *root,
4223 u64 bytenr, u64 num_bytes, int reserved)
4224 {
4225 struct btrfs_block_group_cache *cache;
4226
4227 cache = btrfs_lookup_block_group(root->fs_info, bytenr);
4228 BUG_ON(!cache);
4229
4230 pin_down_extent(root, cache, bytenr, num_bytes, reserved);
4231
4232 btrfs_put_block_group(cache);
4233 return 0;
4234 }
4235
4236 /*
4237 * update size of reserved extents. this function may return -EAGAIN
4238 * if 'reserve' is true or 'sinfo' is false.
4239 */
4240 int btrfs_update_reserved_bytes(struct btrfs_block_group_cache *cache,
4241 u64 num_bytes, int reserve, int sinfo)
4242 {
4243 int ret = 0;
4244 if (sinfo) {
4245 struct btrfs_space_info *space_info = cache->space_info;
4246 spin_lock(&space_info->lock);
4247 spin_lock(&cache->lock);
4248 if (reserve) {
4249 if (cache->ro) {
4250 ret = -EAGAIN;
4251 } else {
4252 cache->reserved += num_bytes;
4253 space_info->bytes_reserved += num_bytes;
4254 }
4255 } else {
4256 if (cache->ro)
4257 space_info->bytes_readonly += num_bytes;
4258 cache->reserved -= num_bytes;
4259 space_info->bytes_reserved -= num_bytes;
4260 space_info->reservation_progress++;
4261 }
4262 spin_unlock(&cache->lock);
4263 spin_unlock(&space_info->lock);
4264 } else {
4265 spin_lock(&cache->lock);
4266 if (cache->ro) {
4267 ret = -EAGAIN;
4268 } else {
4269 if (reserve)
4270 cache->reserved += num_bytes;
4271 else
4272 cache->reserved -= num_bytes;
4273 }
4274 spin_unlock(&cache->lock);
4275 }
4276 return ret;
4277 }
4278
4279 int btrfs_prepare_extent_commit(struct btrfs_trans_handle *trans,
4280 struct btrfs_root *root)
4281 {
4282 struct btrfs_fs_info *fs_info = root->fs_info;
4283 struct btrfs_caching_control *next;
4284 struct btrfs_caching_control *caching_ctl;
4285 struct btrfs_block_group_cache *cache;
4286
4287 down_write(&fs_info->extent_commit_sem);
4288
4289 list_for_each_entry_safe(caching_ctl, next,
4290 &fs_info->caching_block_groups, list) {
4291 cache = caching_ctl->block_group;
4292 if (block_group_cache_done(cache)) {
4293 cache->last_byte_to_unpin = (u64)-1;
4294 list_del_init(&caching_ctl->list);
4295 put_caching_control(caching_ctl);
4296 } else {
4297 cache->last_byte_to_unpin = caching_ctl->progress;
4298 }
4299 }
4300
4301 if (fs_info->pinned_extents == &fs_info->freed_extents[0])
4302 fs_info->pinned_extents = &fs_info->freed_extents[1];
4303 else
4304 fs_info->pinned_extents = &fs_info->freed_extents[0];
4305
4306 up_write(&fs_info->extent_commit_sem);
4307
4308 update_global_block_rsv(fs_info);
4309 return 0;
4310 }
4311
4312 static int unpin_extent_range(struct btrfs_root *root, u64 start, u64 end)
4313 {
4314 struct btrfs_fs_info *fs_info = root->fs_info;
4315 struct btrfs_block_group_cache *cache = NULL;
4316 u64 len;
4317
4318 while (start <= end) {
4319 if (!cache ||
4320 start >= cache->key.objectid + cache->key.offset) {
4321 if (cache)
4322 btrfs_put_block_group(cache);
4323 cache = btrfs_lookup_block_group(fs_info, start);
4324 BUG_ON(!cache);
4325 }
4326
4327 len = cache->key.objectid + cache->key.offset - start;
4328 len = min(len, end + 1 - start);
4329
4330 if (start < cache->last_byte_to_unpin) {
4331 len = min(len, cache->last_byte_to_unpin - start);
4332 btrfs_add_free_space(cache, start, len);
4333 }
4334
4335 start += len;
4336
4337 spin_lock(&cache->space_info->lock);
4338 spin_lock(&cache->lock);
4339 cache->pinned -= len;
4340 cache->space_info->bytes_pinned -= len;
4341 if (cache->ro) {
4342 cache->space_info->bytes_readonly += len;
4343 } else if (cache->reserved_pinned > 0) {
4344 len = min(len, cache->reserved_pinned);
4345 cache->reserved_pinned -= len;
4346 cache->space_info->bytes_reserved += len;
4347 }
4348 spin_unlock(&cache->lock);
4349 spin_unlock(&cache->space_info->lock);
4350 }
4351
4352 if (cache)
4353 btrfs_put_block_group(cache);
4354 return 0;
4355 }
4356
4357 int btrfs_finish_extent_commit(struct btrfs_trans_handle *trans,
4358 struct btrfs_root *root)
4359 {
4360 struct btrfs_fs_info *fs_info = root->fs_info;
4361 struct extent_io_tree *unpin;
4362 struct btrfs_block_rsv *block_rsv;
4363 struct btrfs_block_rsv *next_rsv;
4364 u64 start;
4365 u64 end;
4366 int idx;
4367 int ret;
4368
4369 if (fs_info->pinned_extents == &fs_info->freed_extents[0])
4370 unpin = &fs_info->freed_extents[1];
4371 else
4372 unpin = &fs_info->freed_extents[0];
4373
4374 while (1) {
4375 ret = find_first_extent_bit(unpin, 0, &start, &end,
4376 EXTENT_DIRTY);
4377 if (ret)
4378 break;
4379
4380 if (btrfs_test_opt(root, DISCARD))
4381 ret = btrfs_discard_extent(root, start,
4382 end + 1 - start, NULL);
4383
4384 clear_extent_dirty(unpin, start, end, GFP_NOFS);
4385 unpin_extent_range(root, start, end);
4386 cond_resched();
4387 }
4388
4389 mutex_lock(&fs_info->durable_block_rsv_mutex);
4390 list_for_each_entry_safe(block_rsv, next_rsv,
4391 &fs_info->durable_block_rsv_list, list) {
4392
4393 idx = trans->transid & 0x1;
4394 if (block_rsv->freed[idx] > 0) {
4395 block_rsv_add_bytes(block_rsv,
4396 block_rsv->freed[idx], 0);
4397 block_rsv->freed[idx] = 0;
4398 }
4399 if (atomic_read(&block_rsv->usage) == 0) {
4400 btrfs_block_rsv_release(root, block_rsv, (u64)-1);
4401
4402 if (block_rsv->freed[0] == 0 &&
4403 block_rsv->freed[1] == 0) {
4404 list_del_init(&block_rsv->list);
4405 kfree(block_rsv);
4406 }
4407 } else {
4408 btrfs_block_rsv_release(root, block_rsv, 0);
4409 }
4410 }
4411 mutex_unlock(&fs_info->durable_block_rsv_mutex);
4412
4413 return 0;
4414 }
4415
4416 static int __btrfs_free_extent(struct btrfs_trans_handle *trans,
4417 struct btrfs_root *root,
4418 u64 bytenr, u64 num_bytes, u64 parent,
4419 u64 root_objectid, u64 owner_objectid,
4420 u64 owner_offset, int refs_to_drop,
4421 struct btrfs_delayed_extent_op *extent_op)
4422 {
4423 struct btrfs_key key;
4424 struct btrfs_path *path;
4425 struct btrfs_fs_info *info = root->fs_info;
4426 struct btrfs_root *extent_root = info->extent_root;
4427 struct extent_buffer *leaf;
4428 struct btrfs_extent_item *ei;
4429 struct btrfs_extent_inline_ref *iref;
4430 int ret;
4431 int is_data;
4432 int extent_slot = 0;
4433 int found_extent = 0;
4434 int num_to_del = 1;
4435 u32 item_size;
4436 u64 refs;
4437
4438 path = btrfs_alloc_path();
4439 if (!path)
4440 return -ENOMEM;
4441
4442 path->reada = 1;
4443 path->leave_spinning = 1;
4444
4445 is_data = owner_objectid >= BTRFS_FIRST_FREE_OBJECTID;
4446 BUG_ON(!is_data && refs_to_drop != 1);
4447
4448 ret = lookup_extent_backref(trans, extent_root, path, &iref,
4449 bytenr, num_bytes, parent,
4450 root_objectid, owner_objectid,
4451 owner_offset);
4452 if (ret == 0) {
4453 extent_slot = path->slots[0];
4454 while (extent_slot >= 0) {
4455 btrfs_item_key_to_cpu(path->nodes[0], &key,
4456 extent_slot);
4457 if (key.objectid != bytenr)
4458 break;
4459 if (key.type == BTRFS_EXTENT_ITEM_KEY &&
4460 key.offset == num_bytes) {
4461 found_extent = 1;
4462 break;
4463 }
4464 if (path->slots[0] - extent_slot > 5)
4465 break;
4466 extent_slot--;
4467 }
4468 #ifdef BTRFS_COMPAT_EXTENT_TREE_V0
4469 item_size = btrfs_item_size_nr(path->nodes[0], extent_slot);
4470 if (found_extent && item_size < sizeof(*ei))
4471 found_extent = 0;
4472 #endif
4473 if (!found_extent) {
4474 BUG_ON(iref);
4475 ret = remove_extent_backref(trans, extent_root, path,
4476 NULL, refs_to_drop,
4477 is_data);
4478 BUG_ON(ret);
4479 btrfs_release_path(extent_root, path);
4480 path->leave_spinning = 1;
4481
4482 key.objectid = bytenr;
4483 key.type = BTRFS_EXTENT_ITEM_KEY;
4484 key.offset = num_bytes;
4485
4486 ret = btrfs_search_slot(trans, extent_root,
4487 &key, path, -1, 1);
4488 if (ret) {
4489 printk(KERN_ERR "umm, got %d back from search"
4490 ", was looking for %llu\n", ret,
4491 (unsigned long long)bytenr);
4492 btrfs_print_leaf(extent_root, path->nodes[0]);
4493 }
4494 BUG_ON(ret);
4495 extent_slot = path->slots[0];
4496 }
4497 } else {
4498 btrfs_print_leaf(extent_root, path->nodes[0]);
4499 WARN_ON(1);
4500 printk(KERN_ERR "btrfs unable to find ref byte nr %llu "
4501 "parent %llu root %llu owner %llu offset %llu\n",
4502 (unsigned long long)bytenr,
4503 (unsigned long long)parent,
4504 (unsigned long long)root_objectid,
4505 (unsigned long long)owner_objectid,
4506 (unsigned long long)owner_offset);
4507 }
4508
4509 leaf = path->nodes[0];
4510 item_size = btrfs_item_size_nr(leaf, extent_slot);
4511 #ifdef BTRFS_COMPAT_EXTENT_TREE_V0
4512 if (item_size < sizeof(*ei)) {
4513 BUG_ON(found_extent || extent_slot != path->slots[0]);
4514 ret = convert_extent_item_v0(trans, extent_root, path,
4515 owner_objectid, 0);
4516 BUG_ON(ret < 0);
4517
4518 btrfs_release_path(extent_root, path);
4519 path->leave_spinning = 1;
4520
4521 key.objectid = bytenr;
4522 key.type = BTRFS_EXTENT_ITEM_KEY;
4523 key.offset = num_bytes;
4524
4525 ret = btrfs_search_slot(trans, extent_root, &key, path,
4526 -1, 1);
4527 if (ret) {
4528 printk(KERN_ERR "umm, got %d back from search"
4529 ", was looking for %llu\n", ret,
4530 (unsigned long long)bytenr);
4531 btrfs_print_leaf(extent_root, path->nodes[0]);
4532 }
4533 BUG_ON(ret);
4534 extent_slot = path->slots[0];
4535 leaf = path->nodes[0];
4536 item_size = btrfs_item_size_nr(leaf, extent_slot);
4537 }
4538 #endif
4539 BUG_ON(item_size < sizeof(*ei));
4540 ei = btrfs_item_ptr(leaf, extent_slot,
4541 struct btrfs_extent_item);
4542 if (owner_objectid < BTRFS_FIRST_FREE_OBJECTID) {
4543 struct btrfs_tree_block_info *bi;
4544 BUG_ON(item_size < sizeof(*ei) + sizeof(*bi));
4545 bi = (struct btrfs_tree_block_info *)(ei + 1);
4546 WARN_ON(owner_objectid != btrfs_tree_block_level(leaf, bi));
4547 }
4548
4549 refs = btrfs_extent_refs(leaf, ei);
4550 BUG_ON(refs < refs_to_drop);
4551 refs -= refs_to_drop;
4552
4553 if (refs > 0) {
4554 if (extent_op)
4555 __run_delayed_extent_op(extent_op, leaf, ei);
4556 /*
4557 * In the case of inline back ref, reference count will
4558 * be updated by remove_extent_backref
4559 */
4560 if (iref) {
4561 BUG_ON(!found_extent);
4562 } else {
4563 btrfs_set_extent_refs(leaf, ei, refs);
4564 btrfs_mark_buffer_dirty(leaf);
4565 }
4566 if (found_extent) {
4567 ret = remove_extent_backref(trans, extent_root, path,
4568 iref, refs_to_drop,
4569 is_data);
4570 BUG_ON(ret);
4571 }
4572 } else {
4573 if (found_extent) {
4574 BUG_ON(is_data && refs_to_drop !=
4575 extent_data_ref_count(root, path, iref));
4576 if (iref) {
4577 BUG_ON(path->slots[0] != extent_slot);
4578 } else {
4579 BUG_ON(path->slots[0] != extent_slot + 1);
4580 path->slots[0] = extent_slot;
4581 num_to_del = 2;
4582 }
4583 }
4584
4585 ret = btrfs_del_items(trans, extent_root, path, path->slots[0],
4586 num_to_del);
4587 BUG_ON(ret);
4588 btrfs_release_path(extent_root, path);
4589
4590 if (is_data) {
4591 ret = btrfs_del_csums(trans, root, bytenr, num_bytes);
4592 BUG_ON(ret);
4593 } else {
4594 invalidate_mapping_pages(info->btree_inode->i_mapping,
4595 bytenr >> PAGE_CACHE_SHIFT,
4596 (bytenr + num_bytes - 1) >> PAGE_CACHE_SHIFT);
4597 }
4598
4599 ret = update_block_group(trans, root, bytenr, num_bytes, 0);
4600 BUG_ON(ret);
4601 }
4602 btrfs_free_path(path);
4603 return ret;
4604 }
4605
4606 /*
4607 * when we free an block, it is possible (and likely) that we free the last
4608 * delayed ref for that extent as well. This searches the delayed ref tree for
4609 * a given extent, and if there are no other delayed refs to be processed, it
4610 * removes it from the tree.
4611 */
4612 static noinline int check_ref_cleanup(struct btrfs_trans_handle *trans,
4613 struct btrfs_root *root, u64 bytenr)
4614 {
4615 struct btrfs_delayed_ref_head *head;
4616 struct btrfs_delayed_ref_root *delayed_refs;
4617 struct btrfs_delayed_ref_node *ref;
4618 struct rb_node *node;
4619 int ret = 0;
4620
4621 delayed_refs = &trans->transaction->delayed_refs;
4622 spin_lock(&delayed_refs->lock);
4623 head = btrfs_find_delayed_ref_head(trans, bytenr);
4624 if (!head)
4625 goto out;
4626
4627 node = rb_prev(&head->node.rb_node);
4628 if (!node)
4629 goto out;
4630
4631 ref = rb_entry(node, struct btrfs_delayed_ref_node, rb_node);
4632
4633 /* there are still entries for this ref, we can't drop it */
4634 if (ref->bytenr == bytenr)
4635 goto out;
4636
4637 if (head->extent_op) {
4638 if (!head->must_insert_reserved)
4639 goto out;
4640 kfree(head->extent_op);
4641 head->extent_op = NULL;
4642 }
4643
4644 /*
4645 * waiting for the lock here would deadlock. If someone else has it
4646 * locked they are already in the process of dropping it anyway
4647 */
4648 if (!mutex_trylock(&head->mutex))
4649 goto out;
4650
4651 /*
4652 * at this point we have a head with no other entries. Go
4653 * ahead and process it.
4654 */
4655 head->node.in_tree = 0;
4656 rb_erase(&head->node.rb_node, &delayed_refs->root);
4657
4658 delayed_refs->num_entries--;
4659
4660 /*
4661 * we don't take a ref on the node because we're removing it from the
4662 * tree, so we just steal the ref the tree was holding.
4663 */
4664 delayed_refs->num_heads--;
4665 if (list_empty(&head->cluster))
4666 delayed_refs->num_heads_ready--;
4667
4668 list_del_init(&head->cluster);
4669 spin_unlock(&delayed_refs->lock);
4670
4671 BUG_ON(head->extent_op);
4672 if (head->must_insert_reserved)
4673 ret = 1;
4674
4675 mutex_unlock(&head->mutex);
4676 btrfs_put_delayed_ref(&head->node);
4677 return ret;
4678 out:
4679 spin_unlock(&delayed_refs->lock);
4680 return 0;
4681 }
4682
4683 void btrfs_free_tree_block(struct btrfs_trans_handle *trans,
4684 struct btrfs_root *root,
4685 struct extent_buffer *buf,
4686 u64 parent, int last_ref)
4687 {
4688 struct btrfs_block_rsv *block_rsv;
4689 struct btrfs_block_group_cache *cache = NULL;
4690 int ret;
4691
4692 if (root->root_key.objectid != BTRFS_TREE_LOG_OBJECTID) {
4693 ret = btrfs_add_delayed_tree_ref(trans, buf->start, buf->len,
4694 parent, root->root_key.objectid,
4695 btrfs_header_level(buf),
4696 BTRFS_DROP_DELAYED_REF, NULL);
4697 BUG_ON(ret);
4698 }
4699
4700 if (!last_ref)
4701 return;
4702
4703 block_rsv = get_block_rsv(trans, root);
4704 cache = btrfs_lookup_block_group(root->fs_info, buf->start);
4705 if (block_rsv->space_info != cache->space_info)
4706 goto out;
4707
4708 if (btrfs_header_generation(buf) == trans->transid) {
4709 if (root->root_key.objectid != BTRFS_TREE_LOG_OBJECTID) {
4710 ret = check_ref_cleanup(trans, root, buf->start);
4711 if (!ret)
4712 goto pin;
4713 }
4714
4715 if (btrfs_header_flag(buf, BTRFS_HEADER_FLAG_WRITTEN)) {
4716 pin_down_extent(root, cache, buf->start, buf->len, 1);
4717 goto pin;
4718 }
4719
4720 WARN_ON(test_bit(EXTENT_BUFFER_DIRTY, &buf->bflags));
4721
4722 btrfs_add_free_space(cache, buf->start, buf->len);
4723 ret = btrfs_update_reserved_bytes(cache, buf->len, 0, 0);
4724 if (ret == -EAGAIN) {
4725 /* block group became read-only */
4726 btrfs_update_reserved_bytes(cache, buf->len, 0, 1);
4727 goto out;
4728 }
4729
4730 ret = 1;
4731 spin_lock(&block_rsv->lock);
4732 if (block_rsv->reserved < block_rsv->size) {
4733 block_rsv->reserved += buf->len;
4734 ret = 0;
4735 }
4736 spin_unlock(&block_rsv->lock);
4737
4738 if (ret) {
4739 spin_lock(&cache->space_info->lock);
4740 cache->space_info->bytes_reserved -= buf->len;
4741 cache->space_info->reservation_progress++;
4742 spin_unlock(&cache->space_info->lock);
4743 }
4744 goto out;
4745 }
4746 pin:
4747 if (block_rsv->durable && !cache->ro) {
4748 ret = 0;
4749 spin_lock(&cache->lock);
4750 if (!cache->ro) {
4751 cache->reserved_pinned += buf->len;
4752 ret = 1;
4753 }
4754 spin_unlock(&cache->lock);
4755
4756 if (ret) {
4757 spin_lock(&block_rsv->lock);
4758 block_rsv->freed[trans->transid & 0x1] += buf->len;
4759 spin_unlock(&block_rsv->lock);
4760 }
4761 }
4762 out:
4763 /*
4764 * Deleting the buffer, clear the corrupt flag since it doesn't matter
4765 * anymore.
4766 */
4767 clear_bit(EXTENT_BUFFER_CORRUPT, &buf->bflags);
4768 btrfs_put_block_group(cache);
4769 }
4770
4771 int btrfs_free_extent(struct btrfs_trans_handle *trans,
4772 struct btrfs_root *root,
4773 u64 bytenr, u64 num_bytes, u64 parent,
4774 u64 root_objectid, u64 owner, u64 offset)
4775 {
4776 int ret;
4777
4778 /*
4779 * tree log blocks never actually go into the extent allocation
4780 * tree, just update pinning info and exit early.
4781 */
4782 if (root_objectid == BTRFS_TREE_LOG_OBJECTID) {
4783 WARN_ON(owner >= BTRFS_FIRST_FREE_OBJECTID);
4784 /* unlocks the pinned mutex */
4785 btrfs_pin_extent(root, bytenr, num_bytes, 1);
4786 ret = 0;
4787 } else if (owner < BTRFS_FIRST_FREE_OBJECTID) {
4788 ret = btrfs_add_delayed_tree_ref(trans, bytenr, num_bytes,
4789 parent, root_objectid, (int)owner,
4790 BTRFS_DROP_DELAYED_REF, NULL);
4791 BUG_ON(ret);
4792 } else {
4793 ret = btrfs_add_delayed_data_ref(trans, bytenr, num_bytes,
4794 parent, root_objectid, owner,
4795 offset, BTRFS_DROP_DELAYED_REF, NULL);
4796 BUG_ON(ret);
4797 }
4798 return ret;
4799 }
4800
4801 static u64 stripe_align(struct btrfs_root *root, u64 val)
4802 {
4803 u64 mask = ((u64)root->stripesize - 1);
4804 u64 ret = (val + mask) & ~mask;
4805 return ret;
4806 }
4807
4808 /*
4809 * when we wait for progress in the block group caching, its because
4810 * our allocation attempt failed at least once. So, we must sleep
4811 * and let some progress happen before we try again.
4812 *
4813 * This function will sleep at least once waiting for new free space to
4814 * show up, and then it will check the block group free space numbers
4815 * for our min num_bytes. Another option is to have it go ahead
4816 * and look in the rbtree for a free extent of a given size, but this
4817 * is a good start.
4818 */
4819 static noinline int
4820 wait_block_group_cache_progress(struct btrfs_block_group_cache *cache,
4821 u64 num_bytes)
4822 {
4823 struct btrfs_caching_control *caching_ctl;
4824 DEFINE_WAIT(wait);
4825
4826 caching_ctl = get_caching_control(cache);
4827 if (!caching_ctl)
4828 return 0;
4829
4830 wait_event(caching_ctl->wait, block_group_cache_done(cache) ||
4831 (cache->free_space >= num_bytes));
4832
4833 put_caching_control(caching_ctl);
4834 return 0;
4835 }
4836
4837 static noinline int
4838 wait_block_group_cache_done(struct btrfs_block_group_cache *cache)
4839 {
4840 struct btrfs_caching_control *caching_ctl;
4841 DEFINE_WAIT(wait);
4842
4843 caching_ctl = get_caching_control(cache);
4844 if (!caching_ctl)
4845 return 0;
4846
4847 wait_event(caching_ctl->wait, block_group_cache_done(cache));
4848
4849 put_caching_control(caching_ctl);
4850 return 0;
4851 }
4852
4853 static int get_block_group_index(struct btrfs_block_group_cache *cache)
4854 {
4855 int index;
4856 if (cache->flags & BTRFS_BLOCK_GROUP_RAID10)
4857 index = 0;
4858 else if (cache->flags & BTRFS_BLOCK_GROUP_RAID1)
4859 index = 1;
4860 else if (cache->flags & BTRFS_BLOCK_GROUP_DUP)
4861 index = 2;
4862 else if (cache->flags & BTRFS_BLOCK_GROUP_RAID0)
4863 index = 3;
4864 else
4865 index = 4;
4866 return index;
4867 }
4868
4869 enum btrfs_loop_type {
4870 LOOP_FIND_IDEAL = 0,
4871 LOOP_CACHING_NOWAIT = 1,
4872 LOOP_CACHING_WAIT = 2,
4873 LOOP_ALLOC_CHUNK = 3,
4874 LOOP_NO_EMPTY_SIZE = 4,
4875 };
4876
4877 /*
4878 * walks the btree of allocated extents and find a hole of a given size.
4879 * The key ins is changed to record the hole:
4880 * ins->objectid == block start
4881 * ins->flags = BTRFS_EXTENT_ITEM_KEY
4882 * ins->offset == number of blocks
4883 * Any available blocks before search_start are skipped.
4884 */
4885 static noinline int find_free_extent(struct btrfs_trans_handle *trans,
4886 struct btrfs_root *orig_root,
4887 u64 num_bytes, u64 empty_size,
4888 u64 search_start, u64 search_end,
4889 u64 hint_byte, struct btrfs_key *ins,
4890 int data)
4891 {
4892 int ret = 0;
4893 struct btrfs_root *root = orig_root->fs_info->extent_root;
4894 struct btrfs_free_cluster *last_ptr = NULL;
4895 struct btrfs_block_group_cache *block_group = NULL;
4896 int empty_cluster = 2 * 1024 * 1024;
4897 int allowed_chunk_alloc = 0;
4898 int done_chunk_alloc = 0;
4899 struct btrfs_space_info *space_info;
4900 int last_ptr_loop = 0;
4901 int loop = 0;
4902 int index = 0;
4903 bool found_uncached_bg = false;
4904 bool failed_cluster_refill = false;
4905 bool failed_alloc = false;
4906 bool use_cluster = true;
4907 u64 ideal_cache_percent = 0;
4908 u64 ideal_cache_offset = 0;
4909
4910 WARN_ON(num_bytes < root->sectorsize);
4911 btrfs_set_key_type(ins, BTRFS_EXTENT_ITEM_KEY);
4912 ins->objectid = 0;
4913 ins->offset = 0;
4914
4915 space_info = __find_space_info(root->fs_info, data);
4916 if (!space_info) {
4917 printk(KERN_ERR "No space info for %d\n", data);
4918 return -ENOSPC;
4919 }
4920
4921 /*
4922 * If the space info is for both data and metadata it means we have a
4923 * small filesystem and we can't use the clustering stuff.
4924 */
4925 if (btrfs_mixed_space_info(space_info))
4926 use_cluster = false;
4927
4928 if (orig_root->ref_cows || empty_size)
4929 allowed_chunk_alloc = 1;
4930
4931 if (data & BTRFS_BLOCK_GROUP_METADATA && use_cluster) {
4932 last_ptr = &root->fs_info->meta_alloc_cluster;
4933 if (!btrfs_test_opt(root, SSD))
4934 empty_cluster = 64 * 1024;
4935 }
4936
4937 if ((data & BTRFS_BLOCK_GROUP_DATA) && use_cluster &&
4938 btrfs_test_opt(root, SSD)) {
4939 last_ptr = &root->fs_info->data_alloc_cluster;
4940 }
4941
4942 if (last_ptr) {
4943 spin_lock(&last_ptr->lock);
4944 if (last_ptr->block_group)
4945 hint_byte = last_ptr->window_start;
4946 spin_unlock(&last_ptr->lock);
4947 }
4948
4949 search_start = max(search_start, first_logical_byte(root, 0));
4950 search_start = max(search_start, hint_byte);
4951
4952 if (!last_ptr)
4953 empty_cluster = 0;
4954
4955 if (search_start == hint_byte) {
4956 ideal_cache:
4957 block_group = btrfs_lookup_block_group(root->fs_info,
4958 search_start);
4959 /*
4960 * we don't want to use the block group if it doesn't match our
4961 * allocation bits, or if its not cached.
4962 *
4963 * However if we are re-searching with an ideal block group
4964 * picked out then we don't care that the block group is cached.
4965 */
4966 if (block_group && block_group_bits(block_group, data) &&
4967 (block_group->cached != BTRFS_CACHE_NO ||
4968 search_start == ideal_cache_offset)) {
4969 down_read(&space_info->groups_sem);
4970 if (list_empty(&block_group->list) ||
4971 block_group->ro) {
4972 /*
4973 * someone is removing this block group,
4974 * we can't jump into the have_block_group
4975 * target because our list pointers are not
4976 * valid
4977 */
4978 btrfs_put_block_group(block_group);
4979 up_read(&space_info->groups_sem);
4980 } else {
4981 index = get_block_group_index(block_group);
4982 goto have_block_group;
4983 }
4984 } else if (block_group) {
4985 btrfs_put_block_group(block_group);
4986 }
4987 }
4988 search:
4989 down_read(&space_info->groups_sem);
4990 list_for_each_entry(block_group, &space_info->block_groups[index],
4991 list) {
4992 u64 offset;
4993 int cached;
4994
4995 btrfs_get_block_group(block_group);
4996 search_start = block_group->key.objectid;
4997
4998 /*
4999 * this can happen if we end up cycling through all the
5000 * raid types, but we want to make sure we only allocate
5001 * for the proper type.
5002 */
5003 if (!block_group_bits(block_group, data)) {
5004 u64 extra = BTRFS_BLOCK_GROUP_DUP |
5005 BTRFS_BLOCK_GROUP_RAID1 |
5006 BTRFS_BLOCK_GROUP_RAID10;
5007
5008 /*
5009 * if they asked for extra copies and this block group
5010 * doesn't provide them, bail. This does allow us to
5011 * fill raid0 from raid1.
5012 */
5013 if ((data & extra) && !(block_group->flags & extra))
5014 goto loop;
5015 }
5016
5017 have_block_group:
5018 if (unlikely(block_group->cached == BTRFS_CACHE_NO)) {
5019 u64 free_percent;
5020
5021 ret = cache_block_group(block_group, trans,
5022 orig_root, 1);
5023 if (block_group->cached == BTRFS_CACHE_FINISHED)
5024 goto have_block_group;
5025
5026 free_percent = btrfs_block_group_used(&block_group->item);
5027 free_percent *= 100;
5028 free_percent = div64_u64(free_percent,
5029 block_group->key.offset);
5030 free_percent = 100 - free_percent;
5031 if (free_percent > ideal_cache_percent &&
5032 likely(!block_group->ro)) {
5033 ideal_cache_offset = block_group->key.objectid;
5034 ideal_cache_percent = free_percent;
5035 }
5036
5037 /*
5038 * We only want to start kthread caching if we are at
5039 * the point where we will wait for caching to make
5040 * progress, or if our ideal search is over and we've
5041 * found somebody to start caching.
5042 */
5043 if (loop > LOOP_CACHING_NOWAIT ||
5044 (loop > LOOP_FIND_IDEAL &&
5045 atomic_read(&space_info->caching_threads) < 2)) {
5046 ret = cache_block_group(block_group, trans,
5047 orig_root, 0);
5048 BUG_ON(ret);
5049 }
5050 found_uncached_bg = true;
5051
5052 /*
5053 * If loop is set for cached only, try the next block
5054 * group.
5055 */
5056 if (loop == LOOP_FIND_IDEAL)
5057 goto loop;
5058 }
5059
5060 cached = block_group_cache_done(block_group);
5061 if (unlikely(!cached))
5062 found_uncached_bg = true;
5063
5064 if (unlikely(block_group->ro))
5065 goto loop;
5066
5067 /*
5068 * Ok we want to try and use the cluster allocator, so lets look
5069 * there, unless we are on LOOP_NO_EMPTY_SIZE, since we will
5070 * have tried the cluster allocator plenty of times at this
5071 * point and not have found anything, so we are likely way too
5072 * fragmented for the clustering stuff to find anything, so lets
5073 * just skip it and let the allocator find whatever block it can
5074 * find
5075 */
5076 if (last_ptr && loop < LOOP_NO_EMPTY_SIZE) {
5077 /*
5078 * the refill lock keeps out other
5079 * people trying to start a new cluster
5080 */
5081 spin_lock(&last_ptr->refill_lock);
5082 if (last_ptr->block_group &&
5083 (last_ptr->block_group->ro ||
5084 !block_group_bits(last_ptr->block_group, data))) {
5085 offset = 0;
5086 goto refill_cluster;
5087 }
5088
5089 offset = btrfs_alloc_from_cluster(block_group, last_ptr,
5090 num_bytes, search_start);
5091 if (offset) {
5092 /* we have a block, we're done */
5093 spin_unlock(&last_ptr->refill_lock);
5094 goto checks;
5095 }
5096
5097 spin_lock(&last_ptr->lock);
5098 /*
5099 * whoops, this cluster doesn't actually point to
5100 * this block group. Get a ref on the block
5101 * group is does point to and try again
5102 */
5103 if (!last_ptr_loop && last_ptr->block_group &&
5104 last_ptr->block_group != block_group) {
5105
5106 btrfs_put_block_group(block_group);
5107 block_group = last_ptr->block_group;
5108 btrfs_get_block_group(block_group);
5109 spin_unlock(&last_ptr->lock);
5110 spin_unlock(&last_ptr->refill_lock);
5111
5112 last_ptr_loop = 1;
5113 search_start = block_group->key.objectid;
5114 /*
5115 * we know this block group is properly
5116 * in the list because
5117 * btrfs_remove_block_group, drops the
5118 * cluster before it removes the block
5119 * group from the list
5120 */
5121 goto have_block_group;
5122 }
5123 spin_unlock(&last_ptr->lock);
5124 refill_cluster:
5125 /*
5126 * this cluster didn't work out, free it and
5127 * start over
5128 */
5129 btrfs_return_cluster_to_free_space(NULL, last_ptr);
5130
5131 last_ptr_loop = 0;
5132
5133 /* allocate a cluster in this block group */
5134 ret = btrfs_find_space_cluster(trans, root,
5135 block_group, last_ptr,
5136 offset, num_bytes,
5137 empty_cluster + empty_size);
5138 if (ret == 0) {
5139 /*
5140 * now pull our allocation out of this
5141 * cluster
5142 */
5143 offset = btrfs_alloc_from_cluster(block_group,
5144 last_ptr, num_bytes,
5145 search_start);
5146 if (offset) {
5147 /* we found one, proceed */
5148 spin_unlock(&last_ptr->refill_lock);
5149 goto checks;
5150 }
5151 } else if (!cached && loop > LOOP_CACHING_NOWAIT
5152 && !failed_cluster_refill) {
5153 spin_unlock(&last_ptr->refill_lock);
5154
5155 failed_cluster_refill = true;
5156 wait_block_group_cache_progress(block_group,
5157 num_bytes + empty_cluster + empty_size);
5158 goto have_block_group;
5159 }
5160
5161 /*
5162 * at this point we either didn't find a cluster
5163 * or we weren't able to allocate a block from our
5164 * cluster. Free the cluster we've been trying
5165 * to use, and go to the next block group
5166 */
5167 btrfs_return_cluster_to_free_space(NULL, last_ptr);
5168 spin_unlock(&last_ptr->refill_lock);
5169 goto loop;
5170 }
5171
5172 offset = btrfs_find_space_for_alloc(block_group, search_start,
5173 num_bytes, empty_size);
5174 /*
5175 * If we didn't find a chunk, and we haven't failed on this
5176 * block group before, and this block group is in the middle of
5177 * caching and we are ok with waiting, then go ahead and wait
5178 * for progress to be made, and set failed_alloc to true.
5179 *
5180 * If failed_alloc is true then we've already waited on this
5181 * block group once and should move on to the next block group.
5182 */
5183 if (!offset && !failed_alloc && !cached &&
5184 loop > LOOP_CACHING_NOWAIT) {
5185 wait_block_group_cache_progress(block_group,
5186 num_bytes + empty_size);
5187 failed_alloc = true;
5188 goto have_block_group;
5189 } else if (!offset) {
5190 goto loop;
5191 }
5192 checks:
5193 search_start = stripe_align(root, offset);
5194 /* move on to the next group */
5195 if (search_start + num_bytes >= search_end) {
5196 btrfs_add_free_space(block_group, offset, num_bytes);
5197 goto loop;
5198 }
5199
5200 /* move on to the next group */
5201 if (search_start + num_bytes >
5202 block_group->key.objectid + block_group->key.offset) {
5203 btrfs_add_free_space(block_group, offset, num_bytes);
5204 goto loop;
5205 }
5206
5207 ins->objectid = search_start;
5208 ins->offset = num_bytes;
5209
5210 if (offset < search_start)
5211 btrfs_add_free_space(block_group, offset,
5212 search_start - offset);
5213 BUG_ON(offset > search_start);
5214
5215 ret = btrfs_update_reserved_bytes(block_group, num_bytes, 1,
5216 (data & BTRFS_BLOCK_GROUP_DATA));
5217 if (ret == -EAGAIN) {
5218 btrfs_add_free_space(block_group, offset, num_bytes);
5219 goto loop;
5220 }
5221
5222 /* we are all good, lets return */
5223 ins->objectid = search_start;
5224 ins->offset = num_bytes;
5225
5226 if (offset < search_start)
5227 btrfs_add_free_space(block_group, offset,
5228 search_start - offset);
5229 BUG_ON(offset > search_start);
5230 break;
5231 loop:
5232 failed_cluster_refill = false;
5233 failed_alloc = false;
5234 BUG_ON(index != get_block_group_index(block_group));
5235 btrfs_put_block_group(block_group);
5236 }
5237 up_read(&space_info->groups_sem);
5238
5239 if (!ins->objectid && ++index < BTRFS_NR_RAID_TYPES)
5240 goto search;
5241
5242 /* LOOP_FIND_IDEAL, only search caching/cached bg's, and don't wait for
5243 * for them to make caching progress. Also
5244 * determine the best possible bg to cache
5245 * LOOP_CACHING_NOWAIT, search partially cached block groups, kicking
5246 * caching kthreads as we move along
5247 * LOOP_CACHING_WAIT, search everything, and wait if our bg is caching
5248 * LOOP_ALLOC_CHUNK, force a chunk allocation and try again
5249 * LOOP_NO_EMPTY_SIZE, set empty_size and empty_cluster to 0 and try
5250 * again
5251 */
5252 if (!ins->objectid && loop < LOOP_NO_EMPTY_SIZE &&
5253 (found_uncached_bg || empty_size || empty_cluster ||
5254 allowed_chunk_alloc)) {
5255 index = 0;
5256 if (loop == LOOP_FIND_IDEAL && found_uncached_bg) {
5257 found_uncached_bg = false;
5258 loop++;
5259 if (!ideal_cache_percent &&
5260 atomic_read(&space_info->caching_threads))
5261 goto search;
5262
5263 /*
5264 * 1 of the following 2 things have happened so far
5265 *
5266 * 1) We found an ideal block group for caching that
5267 * is mostly full and will cache quickly, so we might
5268 * as well wait for it.
5269 *
5270 * 2) We searched for cached only and we didn't find
5271 * anything, and we didn't start any caching kthreads
5272 * either, so chances are we will loop through and
5273 * start a couple caching kthreads, and then come back
5274 * around and just wait for them. This will be slower
5275 * because we will have 2 caching kthreads reading at
5276 * the same time when we could have just started one
5277 * and waited for it to get far enough to give us an
5278 * allocation, so go ahead and go to the wait caching
5279 * loop.
5280 */
5281 loop = LOOP_CACHING_WAIT;
5282 search_start = ideal_cache_offset;
5283 ideal_cache_percent = 0;
5284 goto ideal_cache;
5285 } else if (loop == LOOP_FIND_IDEAL) {
5286 /*
5287 * Didn't find a uncached bg, wait on anything we find
5288 * next.
5289 */
5290 loop = LOOP_CACHING_WAIT;
5291 goto search;
5292 }
5293
5294 if (loop < LOOP_CACHING_WAIT) {
5295 loop++;
5296 goto search;
5297 }
5298
5299 if (loop == LOOP_ALLOC_CHUNK) {
5300 empty_size = 0;
5301 empty_cluster = 0;
5302 }
5303
5304 if (allowed_chunk_alloc) {
5305 ret = do_chunk_alloc(trans, root, num_bytes +
5306 2 * 1024 * 1024, data, 1);
5307 allowed_chunk_alloc = 0;
5308 done_chunk_alloc = 1;
5309 } else if (!done_chunk_alloc) {
5310 space_info->force_alloc = 1;
5311 }
5312
5313 if (loop < LOOP_NO_EMPTY_SIZE) {
5314 loop++;
5315 goto search;
5316 }
5317 ret = -ENOSPC;
5318 } else if (!ins->objectid) {
5319 ret = -ENOSPC;
5320 }
5321
5322 /* we found what we needed */
5323 if (ins->objectid) {
5324 if (!(data & BTRFS_BLOCK_GROUP_DATA))
5325 trans->block_group = block_group->key.objectid;
5326
5327 btrfs_put_block_group(block_group);
5328 ret = 0;
5329 }
5330
5331 return ret;
5332 }
5333
5334 static void dump_space_info(struct btrfs_space_info *info, u64 bytes,
5335 int dump_block_groups)
5336 {
5337 struct btrfs_block_group_cache *cache;
5338 int index = 0;
5339
5340 spin_lock(&info->lock);
5341 printk(KERN_INFO "space_info has %llu free, is %sfull\n",
5342 (unsigned long long)(info->total_bytes - info->bytes_used -
5343 info->bytes_pinned - info->bytes_reserved -
5344 info->bytes_readonly),
5345 (info->full) ? "" : "not ");
5346 printk(KERN_INFO "space_info total=%llu, used=%llu, pinned=%llu, "
5347 "reserved=%llu, may_use=%llu, readonly=%llu\n",
5348 (unsigned long long)info->total_bytes,
5349 (unsigned long long)info->bytes_used,
5350 (unsigned long long)info->bytes_pinned,
5351 (unsigned long long)info->bytes_reserved,
5352 (unsigned long long)info->bytes_may_use,
5353 (unsigned long long)info->bytes_readonly);
5354 spin_unlock(&info->lock);
5355
5356 if (!dump_block_groups)
5357 return;
5358
5359 down_read(&info->groups_sem);
5360 again:
5361 list_for_each_entry(cache, &info->block_groups[index], list) {
5362 spin_lock(&cache->lock);
5363 printk(KERN_INFO "block group %llu has %llu bytes, %llu used "
5364 "%llu pinned %llu reserved\n",
5365 (unsigned long long)cache->key.objectid,
5366 (unsigned long long)cache->key.offset,
5367 (unsigned long long)btrfs_block_group_used(&cache->item),
5368 (unsigned long long)cache->pinned,
5369 (unsigned long long)cache->reserved);
5370 btrfs_dump_free_space(cache, bytes);
5371 spin_unlock(&cache->lock);
5372 }
5373 if (++index < BTRFS_NR_RAID_TYPES)
5374 goto again;
5375 up_read(&info->groups_sem);
5376 }
5377
5378 int btrfs_reserve_extent(struct btrfs_trans_handle *trans,
5379 struct btrfs_root *root,
5380 u64 num_bytes, u64 min_alloc_size,
5381 u64 empty_size, u64 hint_byte,
5382 u64 search_end, struct btrfs_key *ins,
5383 u64 data)
5384 {
5385 int ret;
5386 u64 search_start = 0;
5387
5388 data = btrfs_get_alloc_profile(root, data);
5389 again:
5390 /*
5391 * the only place that sets empty_size is btrfs_realloc_node, which
5392 * is not called recursively on allocations
5393 */
5394 if (empty_size || root->ref_cows)
5395 ret = do_chunk_alloc(trans, root->fs_info->extent_root,
5396 num_bytes + 2 * 1024 * 1024, data, 0);
5397
5398 WARN_ON(num_bytes < root->sectorsize);
5399 ret = find_free_extent(trans, root, num_bytes, empty_size,
5400 search_start, search_end, hint_byte,
5401 ins, data);
5402
5403 if (ret == -ENOSPC && num_bytes > min_alloc_size) {
5404 num_bytes = num_bytes >> 1;
5405 num_bytes = num_bytes & ~(root->sectorsize - 1);
5406 num_bytes = max(num_bytes, min_alloc_size);
5407 do_chunk_alloc(trans, root->fs_info->extent_root,
5408 num_bytes, data, 1);
5409 goto again;
5410 }
5411 if (ret == -ENOSPC && btrfs_test_opt(root, ENOSPC_DEBUG)) {
5412 struct btrfs_space_info *sinfo;
5413
5414 sinfo = __find_space_info(root->fs_info, data);
5415 printk(KERN_ERR "btrfs allocation failed flags %llu, "
5416 "wanted %llu\n", (unsigned long long)data,
5417 (unsigned long long)num_bytes);
5418 dump_space_info(sinfo, num_bytes, 1);
5419 }
5420
5421 trace_btrfs_reserved_extent_alloc(root, ins->objectid, ins->offset);
5422
5423 return ret;
5424 }
5425
5426 int btrfs_free_reserved_extent(struct btrfs_root *root, u64 start, u64 len)
5427 {
5428 struct btrfs_block_group_cache *cache;
5429 int ret = 0;
5430
5431 cache = btrfs_lookup_block_group(root->fs_info, start);
5432 if (!cache) {
5433 printk(KERN_ERR "Unable to find block group for %llu\n",
5434 (unsigned long long)start);
5435 return -ENOSPC;
5436 }
5437
5438 if (btrfs_test_opt(root, DISCARD))
5439 ret = btrfs_discard_extent(root, start, len, NULL);
5440
5441 btrfs_add_free_space(cache, start, len);
5442 btrfs_update_reserved_bytes(cache, len, 0, 1);
5443 btrfs_put_block_group(cache);
5444
5445 trace_btrfs_reserved_extent_free(root, start, len);
5446
5447 return ret;
5448 }
5449
5450 static int alloc_reserved_file_extent(struct btrfs_trans_handle *trans,
5451 struct btrfs_root *root,
5452 u64 parent, u64 root_objectid,
5453 u64 flags, u64 owner, u64 offset,
5454 struct btrfs_key *ins, int ref_mod)
5455 {
5456 int ret;
5457 struct btrfs_fs_info *fs_info = root->fs_info;
5458 struct btrfs_extent_item *extent_item;
5459 struct btrfs_extent_inline_ref *iref;
5460 struct btrfs_path *path;
5461 struct extent_buffer *leaf;
5462 int type;
5463 u32 size;
5464
5465 if (parent > 0)
5466 type = BTRFS_SHARED_DATA_REF_KEY;
5467 else
5468 type = BTRFS_EXTENT_DATA_REF_KEY;
5469
5470 size = sizeof(*extent_item) + btrfs_extent_inline_ref_size(type);
5471
5472 path = btrfs_alloc_path();
5473 if (!path)
5474 return -ENOMEM;
5475
5476 path->leave_spinning = 1;
5477 ret = btrfs_insert_empty_item(trans, fs_info->extent_root, path,
5478 ins, size);
5479 BUG_ON(ret);
5480
5481 leaf = path->nodes[0];
5482 extent_item = btrfs_item_ptr(leaf, path->slots[0],
5483 struct btrfs_extent_item);
5484 btrfs_set_extent_refs(leaf, extent_item, ref_mod);
5485 btrfs_set_extent_generation(leaf, extent_item, trans->transid);
5486 btrfs_set_extent_flags(leaf, extent_item,
5487 flags | BTRFS_EXTENT_FLAG_DATA);
5488
5489 iref = (struct btrfs_extent_inline_ref *)(extent_item + 1);
5490 btrfs_set_extent_inline_ref_type(leaf, iref, type);
5491 if (parent > 0) {
5492 struct btrfs_shared_data_ref *ref;
5493 ref = (struct btrfs_shared_data_ref *)(iref + 1);
5494 btrfs_set_extent_inline_ref_offset(leaf, iref, parent);
5495 btrfs_set_shared_data_ref_count(leaf, ref, ref_mod);
5496 } else {
5497 struct btrfs_extent_data_ref *ref;
5498 ref = (struct btrfs_extent_data_ref *)(&iref->offset);
5499 btrfs_set_extent_data_ref_root(leaf, ref, root_objectid);
5500 btrfs_set_extent_data_ref_objectid(leaf, ref, owner);
5501 btrfs_set_extent_data_ref_offset(leaf, ref, offset);
5502 btrfs_set_extent_data_ref_count(leaf, ref, ref_mod);
5503 }
5504
5505 btrfs_mark_buffer_dirty(path->nodes[0]);
5506 btrfs_free_path(path);
5507
5508 ret = update_block_group(trans, root, ins->objectid, ins->offset, 1);
5509 if (ret) {
5510 printk(KERN_ERR "btrfs update block group failed for %llu "
5511 "%llu\n", (unsigned long long)ins->objectid,
5512 (unsigned long long)ins->offset);
5513 BUG();
5514 }
5515 return ret;
5516 }
5517
5518 static int alloc_reserved_tree_block(struct btrfs_trans_handle *trans,
5519 struct btrfs_root *root,
5520 u64 parent, u64 root_objectid,
5521 u64 flags, struct btrfs_disk_key *key,
5522 int level, struct btrfs_key *ins)
5523 {
5524 int ret;
5525 struct btrfs_fs_info *fs_info = root->fs_info;
5526 struct btrfs_extent_item *extent_item;
5527 struct btrfs_tree_block_info *block_info;
5528 struct btrfs_extent_inline_ref *iref;
5529 struct btrfs_path *path;
5530 struct extent_buffer *leaf;
5531 u32 size = sizeof(*extent_item) + sizeof(*block_info) + sizeof(*iref);
5532
5533 path = btrfs_alloc_path();
5534 BUG_ON(!path);
5535
5536 path->leave_spinning = 1;
5537 ret = btrfs_insert_empty_item(trans, fs_info->extent_root, path,
5538 ins, size);
5539 BUG_ON(ret);
5540
5541 leaf = path->nodes[0];
5542 extent_item = btrfs_item_ptr(leaf, path->slots[0],
5543 struct btrfs_extent_item);
5544 btrfs_set_extent_refs(leaf, extent_item, 1);
5545 btrfs_set_extent_generation(leaf, extent_item, trans->transid);
5546 btrfs_set_extent_flags(leaf, extent_item,
5547 flags | BTRFS_EXTENT_FLAG_TREE_BLOCK);
5548 block_info = (struct btrfs_tree_block_info *)(extent_item + 1);
5549
5550 btrfs_set_tree_block_key(leaf, block_info, key);
5551 btrfs_set_tree_block_level(leaf, block_info, level);
5552
5553 iref = (struct btrfs_extent_inline_ref *)(block_info + 1);
5554 if (parent > 0) {
5555 BUG_ON(!(flags & BTRFS_BLOCK_FLAG_FULL_BACKREF));
5556 btrfs_set_extent_inline_ref_type(leaf, iref,
5557 BTRFS_SHARED_BLOCK_REF_KEY);
5558 btrfs_set_extent_inline_ref_offset(leaf, iref, parent);
5559 } else {
5560 btrfs_set_extent_inline_ref_type(leaf, iref,
5561 BTRFS_TREE_BLOCK_REF_KEY);
5562 btrfs_set_extent_inline_ref_offset(leaf, iref, root_objectid);
5563 }
5564
5565 btrfs_mark_buffer_dirty(leaf);
5566 btrfs_free_path(path);
5567
5568 ret = update_block_group(trans, root, ins->objectid, ins->offset, 1);
5569 if (ret) {
5570 printk(KERN_ERR "btrfs update block group failed for %llu "
5571 "%llu\n", (unsigned long long)ins->objectid,
5572 (unsigned long long)ins->offset);
5573 BUG();
5574 }
5575 return ret;
5576 }
5577
5578 int btrfs_alloc_reserved_file_extent(struct btrfs_trans_handle *trans,
5579 struct btrfs_root *root,
5580 u64 root_objectid, u64 owner,
5581 u64 offset, struct btrfs_key *ins)
5582 {
5583 int ret;
5584
5585 BUG_ON(root_objectid == BTRFS_TREE_LOG_OBJECTID);
5586
5587 ret = btrfs_add_delayed_data_ref(trans, ins->objectid, ins->offset,
5588 0, root_objectid, owner, offset,
5589 BTRFS_ADD_DELAYED_EXTENT, NULL);
5590 return ret;
5591 }
5592
5593 /*
5594 * this is used by the tree logging recovery code. It records that
5595 * an extent has been allocated and makes sure to clear the free
5596 * space cache bits as well
5597 */
5598 int btrfs_alloc_logged_file_extent(struct btrfs_trans_handle *trans,
5599 struct btrfs_root *root,
5600 u64 root_objectid, u64 owner, u64 offset,
5601 struct btrfs_key *ins)
5602 {
5603 int ret;
5604 struct btrfs_block_group_cache *block_group;
5605 struct btrfs_caching_control *caching_ctl;
5606 u64 start = ins->objectid;
5607 u64 num_bytes = ins->offset;
5608
5609 block_group = btrfs_lookup_block_group(root->fs_info, ins->objectid);
5610 cache_block_group(block_group, trans, NULL, 0);
5611 caching_ctl = get_caching_control(block_group);
5612
5613 if (!caching_ctl) {
5614 BUG_ON(!block_group_cache_done(block_group));
5615 ret = btrfs_remove_free_space(block_group, start, num_bytes);
5616 BUG_ON(ret);
5617 } else {
5618 mutex_lock(&caching_ctl->mutex);
5619
5620 if (start >= caching_ctl->progress) {
5621 ret = add_excluded_extent(root, start, num_bytes);
5622 BUG_ON(ret);
5623 } else if (start + num_bytes <= caching_ctl->progress) {
5624 ret = btrfs_remove_free_space(block_group,
5625 start, num_bytes);
5626 BUG_ON(ret);
5627 } else {
5628 num_bytes = caching_ctl->progress - start;
5629 ret = btrfs_remove_free_space(block_group,
5630 start, num_bytes);
5631 BUG_ON(ret);
5632
5633 start = caching_ctl->progress;
5634 num_bytes = ins->objectid + ins->offset -
5635 caching_ctl->progress;
5636 ret = add_excluded_extent(root, start, num_bytes);
5637 BUG_ON(ret);
5638 }
5639
5640 mutex_unlock(&caching_ctl->mutex);
5641 put_caching_control(caching_ctl);
5642 }
5643
5644 ret = btrfs_update_reserved_bytes(block_group, ins->offset, 1, 1);
5645 BUG_ON(ret);
5646 btrfs_put_block_group(block_group);
5647 ret = alloc_reserved_file_extent(trans, root, 0, root_objectid,
5648 0, owner, offset, ins, 1);
5649 return ret;
5650 }
5651
5652 struct extent_buffer *btrfs_init_new_buffer(struct btrfs_trans_handle *trans,
5653 struct btrfs_root *root,
5654 u64 bytenr, u32 blocksize,
5655 int level)
5656 {
5657 struct extent_buffer *buf;
5658
5659 buf = btrfs_find_create_tree_block(root, bytenr, blocksize);
5660 if (!buf)
5661 return ERR_PTR(-ENOMEM);
5662 btrfs_set_header_generation(buf, trans->transid);
5663 btrfs_set_buffer_lockdep_class(buf, level);
5664 btrfs_tree_lock(buf);
5665 clean_tree_block(trans, root, buf);
5666
5667 btrfs_set_lock_blocking(buf);
5668 btrfs_set_buffer_uptodate(buf);
5669
5670 if (root->root_key.objectid == BTRFS_TREE_LOG_OBJECTID) {
5671 /*
5672 * we allow two log transactions at a time, use different
5673 * EXENT bit to differentiate dirty pages.
5674 */
5675 if (root->log_transid % 2 == 0)
5676 set_extent_dirty(&root->dirty_log_pages, buf->start,
5677 buf->start + buf->len - 1, GFP_NOFS);
5678 else
5679 set_extent_new(&root->dirty_log_pages, buf->start,
5680 buf->start + buf->len - 1, GFP_NOFS);
5681 } else {
5682 set_extent_dirty(&trans->transaction->dirty_pages, buf->start,
5683 buf->start + buf->len - 1, GFP_NOFS);
5684 }
5685 trans->blocks_used++;
5686 /* this returns a buffer locked for blocking */
5687 return buf;
5688 }
5689
5690 static struct btrfs_block_rsv *
5691 use_block_rsv(struct btrfs_trans_handle *trans,
5692 struct btrfs_root *root, u32 blocksize)
5693 {
5694 struct btrfs_block_rsv *block_rsv;
5695 struct btrfs_block_rsv *global_rsv = &root->fs_info->global_block_rsv;
5696 int ret;
5697
5698 block_rsv = get_block_rsv(trans, root);
5699
5700 if (block_rsv->size == 0) {
5701 ret = reserve_metadata_bytes(trans, root, block_rsv,
5702 blocksize, 0);
5703 /*
5704 * If we couldn't reserve metadata bytes try and use some from
5705 * the global reserve.
5706 */
5707 if (ret && block_rsv != global_rsv) {
5708 ret = block_rsv_use_bytes(global_rsv, blocksize);
5709 if (!ret)
5710 return global_rsv;
5711 return ERR_PTR(ret);
5712 } else if (ret) {
5713 return ERR_PTR(ret);
5714 }
5715 return block_rsv;
5716 }
5717
5718 ret = block_rsv_use_bytes(block_rsv, blocksize);
5719 if (!ret)
5720 return block_rsv;
5721 if (ret) {
5722 WARN_ON(1);
5723 ret = reserve_metadata_bytes(trans, root, block_rsv, blocksize,
5724 0);
5725 if (!ret) {
5726 spin_lock(&block_rsv->lock);
5727 block_rsv->size += blocksize;
5728 spin_unlock(&block_rsv->lock);
5729 return block_rsv;
5730 } else if (ret && block_rsv != global_rsv) {
5731 ret = block_rsv_use_bytes(global_rsv, blocksize);
5732 if (!ret)
5733 return global_rsv;
5734 }
5735 }
5736
5737 return ERR_PTR(-ENOSPC);
5738 }
5739
5740 static void unuse_block_rsv(struct btrfs_block_rsv *block_rsv, u32 blocksize)
5741 {
5742 block_rsv_add_bytes(block_rsv, blocksize, 0);
5743 block_rsv_release_bytes(block_rsv, NULL, 0);
5744 }
5745
5746 /*
5747 * finds a free extent and does all the dirty work required for allocation
5748 * returns the key for the extent through ins, and a tree buffer for
5749 * the first block of the extent through buf.
5750 *
5751 * returns the tree buffer or NULL.
5752 */
5753 struct extent_buffer *btrfs_alloc_free_block(struct btrfs_trans_handle *trans,
5754 struct btrfs_root *root, u32 blocksize,
5755 u64 parent, u64 root_objectid,
5756 struct btrfs_disk_key *key, int level,
5757 u64 hint, u64 empty_size)
5758 {
5759 struct btrfs_key ins;
5760 struct btrfs_block_rsv *block_rsv;
5761 struct extent_buffer *buf;
5762 u64 flags = 0;
5763 int ret;
5764
5765
5766 block_rsv = use_block_rsv(trans, root, blocksize);
5767 if (IS_ERR(block_rsv))
5768 return ERR_CAST(block_rsv);
5769
5770 ret = btrfs_reserve_extent(trans, root, blocksize, blocksize,
5771 empty_size, hint, (u64)-1, &ins, 0);
5772 if (ret) {
5773 unuse_block_rsv(block_rsv, blocksize);
5774 return ERR_PTR(ret);
5775 }
5776
5777 buf = btrfs_init_new_buffer(trans, root, ins.objectid,
5778 blocksize, level);
5779 BUG_ON(IS_ERR(buf));
5780
5781 if (root_objectid == BTRFS_TREE_RELOC_OBJECTID) {
5782 if (parent == 0)
5783 parent = ins.objectid;
5784 flags |= BTRFS_BLOCK_FLAG_FULL_BACKREF;
5785 } else
5786 BUG_ON(parent > 0);
5787
5788 if (root_objectid != BTRFS_TREE_LOG_OBJECTID) {
5789 struct btrfs_delayed_extent_op *extent_op;
5790 extent_op = kmalloc(sizeof(*extent_op), GFP_NOFS);
5791 BUG_ON(!extent_op);
5792 if (key)
5793 memcpy(&extent_op->key, key, sizeof(extent_op->key));
5794 else
5795 memset(&extent_op->key, 0, sizeof(extent_op->key));
5796 extent_op->flags_to_set = flags;
5797 extent_op->update_key = 1;
5798 extent_op->update_flags = 1;
5799 extent_op->is_data = 0;
5800
5801 ret = btrfs_add_delayed_tree_ref(trans, ins.objectid,
5802 ins.offset, parent, root_objectid,
5803 level, BTRFS_ADD_DELAYED_EXTENT,
5804 extent_op);
5805 BUG_ON(ret);
5806 }
5807 return buf;
5808 }
5809
5810 struct walk_control {
5811 u64 refs[BTRFS_MAX_LEVEL];
5812 u64 flags[BTRFS_MAX_LEVEL];
5813 struct btrfs_key update_progress;
5814 int stage;
5815 int level;
5816 int shared_level;
5817 int update_ref;
5818 int keep_locks;
5819 int reada_slot;
5820 int reada_count;
5821 };
5822
5823 #define DROP_REFERENCE 1
5824 #define UPDATE_BACKREF 2
5825
5826 static noinline void reada_walk_down(struct btrfs_trans_handle *trans,
5827 struct btrfs_root *root,
5828 struct walk_control *wc,
5829 struct btrfs_path *path)
5830 {
5831 u64 bytenr;
5832 u64 generation;
5833 u64 refs;
5834 u64 flags;
5835 u32 nritems;
5836 u32 blocksize;
5837 struct btrfs_key key;
5838 struct extent_buffer *eb;
5839 int ret;
5840 int slot;
5841 int nread = 0;
5842
5843 if (path->slots[wc->level] < wc->reada_slot) {
5844 wc->reada_count = wc->reada_count * 2 / 3;
5845 wc->reada_count = max(wc->reada_count, 2);
5846 } else {
5847 wc->reada_count = wc->reada_count * 3 / 2;
5848 wc->reada_count = min_t(int, wc->reada_count,
5849 BTRFS_NODEPTRS_PER_BLOCK(root));
5850 }
5851
5852 eb = path->nodes[wc->level];
5853 nritems = btrfs_header_nritems(eb);
5854 blocksize = btrfs_level_size(root, wc->level - 1);
5855
5856 for (slot = path->slots[wc->level]; slot < nritems; slot++) {
5857 if (nread >= wc->reada_count)
5858 break;
5859
5860 cond_resched();
5861 bytenr = btrfs_node_blockptr(eb, slot);
5862 generation = btrfs_node_ptr_generation(eb, slot);
5863
5864 if (slot == path->slots[wc->level])
5865 goto reada;
5866
5867 if (wc->stage == UPDATE_BACKREF &&
5868 generation <= root->root_key.offset)
5869 continue;
5870
5871 /* We don't lock the tree block, it's OK to be racy here */
5872 ret = btrfs_lookup_extent_info(trans, root, bytenr, blocksize,
5873 &refs, &flags);
5874 BUG_ON(ret);
5875 BUG_ON(refs == 0);
5876
5877 if (wc->stage == DROP_REFERENCE) {
5878 if (refs == 1)
5879 goto reada;
5880
5881 if (wc->level == 1 &&
5882 (flags & BTRFS_BLOCK_FLAG_FULL_BACKREF))
5883 continue;
5884 if (!wc->update_ref ||
5885 generation <= root->root_key.offset)
5886 continue;
5887 btrfs_node_key_to_cpu(eb, &key, slot);
5888 ret = btrfs_comp_cpu_keys(&key,
5889 &wc->update_progress);
5890 if (ret < 0)
5891 continue;
5892 } else {
5893 if (wc->level == 1 &&
5894 (flags & BTRFS_BLOCK_FLAG_FULL_BACKREF))
5895 continue;
5896 }
5897 reada:
5898 ret = readahead_tree_block(root, bytenr, blocksize,
5899 generation);
5900 if (ret)
5901 break;
5902 nread++;
5903 }
5904 wc->reada_slot = slot;
5905 }
5906
5907 /*
5908 * hepler to process tree block while walking down the tree.
5909 *
5910 * when wc->stage == UPDATE_BACKREF, this function updates
5911 * back refs for pointers in the block.
5912 *
5913 * NOTE: return value 1 means we should stop walking down.
5914 */
5915 static noinline int walk_down_proc(struct btrfs_trans_handle *trans,
5916 struct btrfs_root *root,
5917 struct btrfs_path *path,
5918 struct walk_control *wc, int lookup_info)
5919 {
5920 int level = wc->level;
5921 struct extent_buffer *eb = path->nodes[level];
5922 u64 flag = BTRFS_BLOCK_FLAG_FULL_BACKREF;
5923 int ret;
5924
5925 if (wc->stage == UPDATE_BACKREF &&
5926 btrfs_header_owner(eb) != root->root_key.objectid)
5927 return 1;
5928
5929 /*
5930 * when reference count of tree block is 1, it won't increase
5931 * again. once full backref flag is set, we never clear it.
5932 */
5933 if (lookup_info &&
5934 ((wc->stage == DROP_REFERENCE && wc->refs[level] != 1) ||
5935 (wc->stage == UPDATE_BACKREF && !(wc->flags[level] & flag)))) {
5936 BUG_ON(!path->locks[level]);
5937 ret = btrfs_lookup_extent_info(trans, root,
5938 eb->start, eb->len,
5939 &wc->refs[level],
5940 &wc->flags[level]);
5941 BUG_ON(ret);
5942 BUG_ON(wc->refs[level] == 0);
5943 }
5944
5945 if (wc->stage == DROP_REFERENCE) {
5946 if (wc->refs[level] > 1)
5947 return 1;
5948
5949 if (path->locks[level] && !wc->keep_locks) {
5950 btrfs_tree_unlock(eb);
5951 path->locks[level] = 0;
5952 }
5953 return 0;
5954 }
5955
5956 /* wc->stage == UPDATE_BACKREF */
5957 if (!(wc->flags[level] & flag)) {
5958 BUG_ON(!path->locks[level]);
5959 ret = btrfs_inc_ref(trans, root, eb, 1);
5960 BUG_ON(ret);
5961 ret = btrfs_dec_ref(trans, root, eb, 0);
5962 BUG_ON(ret);
5963 ret = btrfs_set_disk_extent_flags(trans, root, eb->start,
5964 eb->len, flag, 0);
5965 BUG_ON(ret);
5966 wc->flags[level] |= flag;
5967 }
5968
5969 /*
5970 * the block is shared by multiple trees, so it's not good to
5971 * keep the tree lock
5972 */
5973 if (path->locks[level] && level > 0) {
5974 btrfs_tree_unlock(eb);
5975 path->locks[level] = 0;
5976 }
5977 return 0;
5978 }
5979
5980 /*
5981 * hepler to process tree block pointer.
5982 *
5983 * when wc->stage == DROP_REFERENCE, this function checks
5984 * reference count of the block pointed to. if the block
5985 * is shared and we need update back refs for the subtree
5986 * rooted at the block, this function changes wc->stage to
5987 * UPDATE_BACKREF. if the block is shared and there is no
5988 * need to update back, this function drops the reference
5989 * to the block.
5990 *
5991 * NOTE: return value 1 means we should stop walking down.
5992 */
5993 static noinline int do_walk_down(struct btrfs_trans_handle *trans,
5994 struct btrfs_root *root,
5995 struct btrfs_path *path,
5996 struct walk_control *wc, int *lookup_info)
5997 {
5998 u64 bytenr;
5999 u64 generation;
6000 u64 parent;
6001 u32 blocksize;
6002 struct btrfs_key key;
6003 struct extent_buffer *next;
6004 int level = wc->level;
6005 int reada = 0;
6006 int ret = 0;
6007
6008 generation = btrfs_node_ptr_generation(path->nodes[level],
6009 path->slots[level]);
6010 /*
6011 * if the lower level block was created before the snapshot
6012 * was created, we know there is no need to update back refs
6013 * for the subtree
6014 */
6015 if (wc->stage == UPDATE_BACKREF &&
6016 generation <= root->root_key.offset) {
6017 *lookup_info = 1;
6018 return 1;
6019 }
6020
6021 bytenr = btrfs_node_blockptr(path->nodes[level], path->slots[level]);
6022 blocksize = btrfs_level_size(root, level - 1);
6023
6024 next = btrfs_find_tree_block(root, bytenr, blocksize);
6025 if (!next) {
6026 next = btrfs_find_create_tree_block(root, bytenr, blocksize);
6027 if (!next)
6028 return -ENOMEM;
6029 reada = 1;
6030 }
6031 btrfs_tree_lock(next);
6032 btrfs_set_lock_blocking(next);
6033
6034 ret = btrfs_lookup_extent_info(trans, root, bytenr, blocksize,
6035 &wc->refs[level - 1],
6036 &wc->flags[level - 1]);
6037 BUG_ON(ret);
6038 BUG_ON(wc->refs[level - 1] == 0);
6039 *lookup_info = 0;
6040
6041 if (wc->stage == DROP_REFERENCE) {
6042 if (wc->refs[level - 1] > 1) {
6043 if (level == 1 &&
6044 (wc->flags[0] & BTRFS_BLOCK_FLAG_FULL_BACKREF))
6045 goto skip;
6046
6047 if (!wc->update_ref ||
6048 generation <= root->root_key.offset)
6049 goto skip;
6050
6051 btrfs_node_key_to_cpu(path->nodes[level], &key,
6052 path->slots[level]);
6053 ret = btrfs_comp_cpu_keys(&key, &wc->update_progress);
6054 if (ret < 0)
6055 goto skip;
6056
6057 wc->stage = UPDATE_BACKREF;
6058 wc->shared_level = level - 1;
6059 }
6060 } else {
6061 if (level == 1 &&
6062 (wc->flags[0] & BTRFS_BLOCK_FLAG_FULL_BACKREF))
6063 goto skip;
6064 }
6065
6066 if (!btrfs_buffer_uptodate(next, generation)) {
6067 btrfs_tree_unlock(next);
6068 free_extent_buffer(next);
6069 next = NULL;
6070 *lookup_info = 1;
6071 }
6072
6073 if (!next) {
6074 if (reada && level == 1)
6075 reada_walk_down(trans, root, wc, path);
6076 next = read_tree_block(root, bytenr, blocksize, generation);
6077 if (!next)
6078 return -EIO;
6079 btrfs_tree_lock(next);
6080 btrfs_set_lock_blocking(next);
6081 }
6082
6083 level--;
6084 BUG_ON(level != btrfs_header_level(next));
6085 path->nodes[level] = next;
6086 path->slots[level] = 0;
6087 path->locks[level] = 1;
6088 wc->level = level;
6089 if (wc->level == 1)
6090 wc->reada_slot = 0;
6091 return 0;
6092 skip:
6093 wc->refs[level - 1] = 0;
6094 wc->flags[level - 1] = 0;
6095 if (wc->stage == DROP_REFERENCE) {
6096 if (wc->flags[level] & BTRFS_BLOCK_FLAG_FULL_BACKREF) {
6097 parent = path->nodes[level]->start;
6098 } else {
6099 BUG_ON(root->root_key.objectid !=
6100 btrfs_header_owner(path->nodes[level]));
6101 parent = 0;
6102 }
6103
6104 ret = btrfs_free_extent(trans, root, bytenr, blocksize, parent,
6105 root->root_key.objectid, level - 1, 0);
6106 BUG_ON(ret);
6107 }
6108 btrfs_tree_unlock(next);
6109 free_extent_buffer(next);
6110 *lookup_info = 1;
6111 return 1;
6112 }
6113
6114 /*
6115 * hepler to process tree block while walking up the tree.
6116 *
6117 * when wc->stage == DROP_REFERENCE, this function drops
6118 * reference count on the block.
6119 *
6120 * when wc->stage == UPDATE_BACKREF, this function changes
6121 * wc->stage back to DROP_REFERENCE if we changed wc->stage
6122 * to UPDATE_BACKREF previously while processing the block.
6123 *
6124 * NOTE: return value 1 means we should stop walking up.
6125 */
6126 static noinline int walk_up_proc(struct btrfs_trans_handle *trans,
6127 struct btrfs_root *root,
6128 struct btrfs_path *path,
6129 struct walk_control *wc)
6130 {
6131 int ret;
6132 int level = wc->level;
6133 struct extent_buffer *eb = path->nodes[level];
6134 u64 parent = 0;
6135
6136 if (wc->stage == UPDATE_BACKREF) {
6137 BUG_ON(wc->shared_level < level);
6138 if (level < wc->shared_level)
6139 goto out;
6140
6141 ret = find_next_key(path, level + 1, &wc->update_progress);
6142 if (ret > 0)
6143 wc->update_ref = 0;
6144
6145 wc->stage = DROP_REFERENCE;
6146 wc->shared_level = -1;
6147 path->slots[level] = 0;
6148
6149 /*
6150 * check reference count again if the block isn't locked.
6151 * we should start walking down the tree again if reference
6152 * count is one.
6153 */
6154 if (!path->locks[level]) {
6155 BUG_ON(level == 0);
6156 btrfs_tree_lock(eb);
6157 btrfs_set_lock_blocking(eb);
6158 path->locks[level] = 1;
6159
6160 ret = btrfs_lookup_extent_info(trans, root,
6161 eb->start, eb->len,
6162 &wc->refs[level],
6163 &wc->flags[level]);
6164 BUG_ON(ret);
6165 BUG_ON(wc->refs[level] == 0);
6166 if (wc->refs[level] == 1) {
6167 btrfs_tree_unlock(eb);
6168 path->locks[level] = 0;
6169 return 1;
6170 }
6171 }
6172 }
6173
6174 /* wc->stage == DROP_REFERENCE */
6175 BUG_ON(wc->refs[level] > 1 && !path->locks[level]);
6176
6177 if (wc->refs[level] == 1) {
6178 if (level == 0) {
6179 if (wc->flags[level] & BTRFS_BLOCK_FLAG_FULL_BACKREF)
6180 ret = btrfs_dec_ref(trans, root, eb, 1);
6181 else
6182 ret = btrfs_dec_ref(trans, root, eb, 0);
6183 BUG_ON(ret);
6184 }
6185 /* make block locked assertion in clean_tree_block happy */
6186 if (!path->locks[level] &&
6187 btrfs_header_generation(eb) == trans->transid) {
6188 btrfs_tree_lock(eb);
6189 btrfs_set_lock_blocking(eb);
6190 path->locks[level] = 1;
6191 }
6192 clean_tree_block(trans, root, eb);
6193 }
6194
6195 if (eb == root->node) {
6196 if (wc->flags[level] & BTRFS_BLOCK_FLAG_FULL_BACKREF)
6197 parent = eb->start;
6198 else
6199 BUG_ON(root->root_key.objectid !=
6200 btrfs_header_owner(eb));
6201 } else {
6202 if (wc->flags[level + 1] & BTRFS_BLOCK_FLAG_FULL_BACKREF)
6203 parent = path->nodes[level + 1]->start;
6204 else
6205 BUG_ON(root->root_key.objectid !=
6206 btrfs_header_owner(path->nodes[level + 1]));
6207 }
6208
6209 btrfs_free_tree_block(trans, root, eb, parent, wc->refs[level] == 1);
6210 out:
6211 wc->refs[level] = 0;
6212 wc->flags[level] = 0;
6213 return 0;
6214 }
6215
6216 static noinline int walk_down_tree(struct btrfs_trans_handle *trans,
6217 struct btrfs_root *root,
6218 struct btrfs_path *path,
6219 struct walk_control *wc)
6220 {
6221 int level = wc->level;
6222 int lookup_info = 1;
6223 int ret;
6224
6225 while (level >= 0) {
6226 ret = walk_down_proc(trans, root, path, wc, lookup_info);
6227 if (ret > 0)
6228 break;
6229
6230 if (level == 0)
6231 break;
6232
6233 if (path->slots[level] >=
6234 btrfs_header_nritems(path->nodes[level]))
6235 break;
6236
6237 ret = do_walk_down(trans, root, path, wc, &lookup_info);
6238 if (ret > 0) {
6239 path->slots[level]++;
6240 continue;
6241 } else if (ret < 0)
6242 return ret;
6243 level = wc->level;
6244 }
6245 return 0;
6246 }
6247
6248 static noinline int walk_up_tree(struct btrfs_trans_handle *trans,
6249 struct btrfs_root *root,
6250 struct btrfs_path *path,
6251 struct walk_control *wc, int max_level)
6252 {
6253 int level = wc->level;
6254 int ret;
6255
6256 path->slots[level] = btrfs_header_nritems(path->nodes[level]);
6257 while (level < max_level && path->nodes[level]) {
6258 wc->level = level;
6259 if (path->slots[level] + 1 <
6260 btrfs_header_nritems(path->nodes[level])) {
6261 path->slots[level]++;
6262 return 0;
6263 } else {
6264 ret = walk_up_proc(trans, root, path, wc);
6265 if (ret > 0)
6266 return 0;
6267
6268 if (path->locks[level]) {
6269 btrfs_tree_unlock(path->nodes[level]);
6270 path->locks[level] = 0;
6271 }
6272 free_extent_buffer(path->nodes[level]);
6273 path->nodes[level] = NULL;
6274 level++;
6275 }
6276 }
6277 return 1;
6278 }
6279
6280 /*
6281 * drop a subvolume tree.
6282 *
6283 * this function traverses the tree freeing any blocks that only
6284 * referenced by the tree.
6285 *
6286 * when a shared tree block is found. this function decreases its
6287 * reference count by one. if update_ref is true, this function
6288 * also make sure backrefs for the shared block and all lower level
6289 * blocks are properly updated.
6290 */
6291 int btrfs_drop_snapshot(struct btrfs_root *root,
6292 struct btrfs_block_rsv *block_rsv, int update_ref)
6293 {
6294 struct btrfs_path *path;
6295 struct btrfs_trans_handle *trans;
6296 struct btrfs_root *tree_root = root->fs_info->tree_root;
6297 struct btrfs_root_item *root_item = &root->root_item;
6298 struct walk_control *wc;
6299 struct btrfs_key key;
6300 int err = 0;
6301 int ret;
6302 int level;
6303
6304 path = btrfs_alloc_path();
6305 BUG_ON(!path);
6306
6307 wc = kzalloc(sizeof(*wc), GFP_NOFS);
6308 BUG_ON(!wc);
6309
6310 trans = btrfs_start_transaction(tree_root, 0);
6311 BUG_ON(IS_ERR(trans));
6312
6313 if (block_rsv)
6314 trans->block_rsv = block_rsv;
6315
6316 if (btrfs_disk_key_objectid(&root_item->drop_progress) == 0) {
6317 level = btrfs_header_level(root->node);
6318 path->nodes[level] = btrfs_lock_root_node(root);
6319 btrfs_set_lock_blocking(path->nodes[level]);
6320 path->slots[level] = 0;
6321 path->locks[level] = 1;
6322 memset(&wc->update_progress, 0,
6323 sizeof(wc->update_progress));
6324 } else {
6325 btrfs_disk_key_to_cpu(&key, &root_item->drop_progress);
6326 memcpy(&wc->update_progress, &key,
6327 sizeof(wc->update_progress));
6328
6329 level = root_item->drop_level;
6330 BUG_ON(level == 0);
6331 path->lowest_level = level;
6332 ret = btrfs_search_slot(NULL, root, &key, path, 0, 0);
6333 path->lowest_level = 0;
6334 if (ret < 0) {
6335 err = ret;
6336 goto out;
6337 }
6338 WARN_ON(ret > 0);
6339
6340 /*
6341 * unlock our path, this is safe because only this
6342 * function is allowed to delete this snapshot
6343 */
6344 btrfs_unlock_up_safe(path, 0);
6345
6346 level = btrfs_header_level(root->node);
6347 while (1) {
6348 btrfs_tree_lock(path->nodes[level]);
6349 btrfs_set_lock_blocking(path->nodes[level]);
6350
6351 ret = btrfs_lookup_extent_info(trans, root,
6352 path->nodes[level]->start,
6353 path->nodes[level]->len,
6354 &wc->refs[level],
6355 &wc->flags[level]);
6356 BUG_ON(ret);
6357 BUG_ON(wc->refs[level] == 0);
6358
6359 if (level == root_item->drop_level)
6360 break;
6361
6362 btrfs_tree_unlock(path->nodes[level]);
6363 WARN_ON(wc->refs[level] != 1);
6364 level--;
6365 }
6366 }
6367
6368 wc->level = level;
6369 wc->shared_level = -1;
6370 wc->stage = DROP_REFERENCE;
6371 wc->update_ref = update_ref;
6372 wc->keep_locks = 0;
6373 wc->reada_count = BTRFS_NODEPTRS_PER_BLOCK(root);
6374
6375 while (1) {
6376 ret = walk_down_tree(trans, root, path, wc);
6377 if (ret < 0) {
6378 err = ret;
6379 break;
6380 }
6381
6382 ret = walk_up_tree(trans, root, path, wc, BTRFS_MAX_LEVEL);
6383 if (ret < 0) {
6384 err = ret;
6385 break;
6386 }
6387
6388 if (ret > 0) {
6389 BUG_ON(wc->stage != DROP_REFERENCE);
6390 break;
6391 }
6392
6393 if (wc->stage == DROP_REFERENCE) {
6394 level = wc->level;
6395 btrfs_node_key(path->nodes[level],
6396 &root_item->drop_progress,
6397 path->slots[level]);
6398 root_item->drop_level = level;
6399 }
6400
6401 BUG_ON(wc->level == 0);
6402 if (btrfs_should_end_transaction(trans, tree_root)) {
6403 ret = btrfs_update_root(trans, tree_root,
6404 &root->root_key,
6405 root_item);
6406 BUG_ON(ret);
6407
6408 btrfs_end_transaction_throttle(trans, tree_root);
6409 trans = btrfs_start_transaction(tree_root, 0);
6410 BUG_ON(IS_ERR(trans));
6411 if (block_rsv)
6412 trans->block_rsv = block_rsv;
6413 }
6414 }
6415 btrfs_release_path(root, path);
6416 BUG_ON(err);
6417
6418 ret = btrfs_del_root(trans, tree_root, &root->root_key);
6419 BUG_ON(ret);
6420
6421 if (root->root_key.objectid != BTRFS_TREE_RELOC_OBJECTID) {
6422 ret = btrfs_find_last_root(tree_root, root->root_key.objectid,
6423 NULL, NULL);
6424 BUG_ON(ret < 0);
6425 if (ret > 0) {
6426 /* if we fail to delete the orphan item this time
6427 * around, it'll get picked up the next time.
6428 *
6429 * The most common failure here is just -ENOENT.
6430 */
6431 btrfs_del_orphan_item(trans, tree_root,
6432 root->root_key.objectid);
6433 }
6434 }
6435
6436 if (root->in_radix) {
6437 btrfs_free_fs_root(tree_root->fs_info, root);
6438 } else {
6439 free_extent_buffer(root->node);
6440 free_extent_buffer(root->commit_root);
6441 kfree(root);
6442 }
6443 out:
6444 btrfs_end_transaction_throttle(trans, tree_root);
6445 kfree(wc);
6446 btrfs_free_path(path);
6447 return err;
6448 }
6449
6450 /*
6451 * drop subtree rooted at tree block 'node'.
6452 *
6453 * NOTE: this function will unlock and release tree block 'node'
6454 */
6455 int btrfs_drop_subtree(struct btrfs_trans_handle *trans,
6456 struct btrfs_root *root,
6457 struct extent_buffer *node,
6458 struct extent_buffer *parent)
6459 {
6460 struct btrfs_path *path;
6461 struct walk_control *wc;
6462 int level;
6463 int parent_level;
6464 int ret = 0;
6465 int wret;
6466
6467 BUG_ON(root->root_key.objectid != BTRFS_TREE_RELOC_OBJECTID);
6468
6469 path = btrfs_alloc_path();
6470 if (!path)
6471 return -ENOMEM;
6472
6473 wc = kzalloc(sizeof(*wc), GFP_NOFS);
6474 if (!wc) {
6475 btrfs_free_path(path);
6476 return -ENOMEM;
6477 }
6478
6479 btrfs_assert_tree_locked(parent);
6480 parent_level = btrfs_header_level(parent);
6481 extent_buffer_get(parent);
6482 path->nodes[parent_level] = parent;
6483 path->slots[parent_level] = btrfs_header_nritems(parent);
6484
6485 btrfs_assert_tree_locked(node);
6486 level = btrfs_header_level(node);
6487 path->nodes[level] = node;
6488 path->slots[level] = 0;
6489 path->locks[level] = 1;
6490
6491 wc->refs[parent_level] = 1;
6492 wc->flags[parent_level] = BTRFS_BLOCK_FLAG_FULL_BACKREF;
6493 wc->level = level;
6494 wc->shared_level = -1;
6495 wc->stage = DROP_REFERENCE;
6496 wc->update_ref = 0;
6497 wc->keep_locks = 1;
6498 wc->reada_count = BTRFS_NODEPTRS_PER_BLOCK(root);
6499
6500 while (1) {
6501 wret = walk_down_tree(trans, root, path, wc);
6502 if (wret < 0) {
6503 ret = wret;
6504 break;
6505 }
6506
6507 wret = walk_up_tree(trans, root, path, wc, parent_level);
6508 if (wret < 0)
6509 ret = wret;
6510 if (wret != 0)
6511 break;
6512 }
6513
6514 kfree(wc);
6515 btrfs_free_path(path);
6516 return ret;
6517 }
6518
6519 #if 0
6520 static unsigned long calc_ra(unsigned long start, unsigned long last,
6521 unsigned long nr)
6522 {
6523 return min(last, start + nr - 1);
6524 }
6525
6526 static noinline int relocate_inode_pages(struct inode *inode, u64 start,
6527 u64 len)
6528 {
6529 u64 page_start;
6530 u64 page_end;
6531 unsigned long first_index;
6532 unsigned long last_index;
6533 unsigned long i;
6534 struct page *page;
6535 struct extent_io_tree *io_tree = &BTRFS_I(inode)->io_tree;
6536 struct file_ra_state *ra;
6537 struct btrfs_ordered_extent *ordered;
6538 unsigned int total_read = 0;
6539 unsigned int total_dirty = 0;
6540 int ret = 0;
6541
6542 ra = kzalloc(sizeof(*ra), GFP_NOFS);
6543 if (!ra)
6544 return -ENOMEM;
6545
6546 mutex_lock(&inode->i_mutex);
6547 first_index = start >> PAGE_CACHE_SHIFT;
6548 last_index = (start + len - 1) >> PAGE_CACHE_SHIFT;
6549
6550 /* make sure the dirty trick played by the caller work */
6551 ret = invalidate_inode_pages2_range(inode->i_mapping,
6552 first_index, last_index);
6553 if (ret)
6554 goto out_unlock;
6555
6556 file_ra_state_init(ra, inode->i_mapping);
6557
6558 for (i = first_index ; i <= last_index; i++) {
6559 if (total_read % ra->ra_pages == 0) {
6560 btrfs_force_ra(inode->i_mapping, ra, NULL, i,
6561 calc_ra(i, last_index, ra->ra_pages));
6562 }
6563 total_read++;
6564 again:
6565 if (((u64)i << PAGE_CACHE_SHIFT) > i_size_read(inode))
6566 BUG_ON(1);
6567 page = grab_cache_page(inode->i_mapping, i);
6568 if (!page) {
6569 ret = -ENOMEM;
6570 goto out_unlock;
6571 }
6572 if (!PageUptodate(page)) {
6573 btrfs_readpage(NULL, page);
6574 lock_page(page);
6575 if (!PageUptodate(page)) {
6576 unlock_page(page);
6577 page_cache_release(page);
6578 ret = -EIO;
6579 goto out_unlock;
6580 }
6581 }
6582 wait_on_page_writeback(page);
6583
6584 page_start = (u64)page->index << PAGE_CACHE_SHIFT;
6585 page_end = page_start + PAGE_CACHE_SIZE - 1;
6586 lock_extent(io_tree, page_start, page_end, GFP_NOFS);
6587
6588 ordered = btrfs_lookup_ordered_extent(inode, page_start);
6589 if (ordered) {
6590 unlock_extent(io_tree, page_start, page_end, GFP_NOFS);
6591 unlock_page(page);
6592 page_cache_release(page);
6593 btrfs_start_ordered_extent(inode, ordered, 1);
6594 btrfs_put_ordered_extent(ordered);
6595 goto again;
6596 }
6597 set_page_extent_mapped(page);
6598
6599 if (i == first_index)
6600 set_extent_bits(io_tree, page_start, page_end,
6601 EXTENT_BOUNDARY, GFP_NOFS);
6602 btrfs_set_extent_delalloc(inode, page_start, page_end);
6603
6604 set_page_dirty(page);
6605 total_dirty++;
6606
6607 unlock_extent(io_tree, page_start, page_end, GFP_NOFS);
6608 unlock_page(page);
6609 page_cache_release(page);
6610 }
6611
6612 out_unlock:
6613 kfree(ra);
6614 mutex_unlock(&inode->i_mutex);
6615 balance_dirty_pages_ratelimited_nr(inode->i_mapping, total_dirty);
6616 return ret;
6617 }
6618
6619 static noinline int relocate_data_extent(struct inode *reloc_inode,
6620 struct btrfs_key *extent_key,
6621 u64 offset)
6622 {
6623 struct btrfs_root *root = BTRFS_I(reloc_inode)->root;
6624 struct extent_map_tree *em_tree = &BTRFS_I(reloc_inode)->extent_tree;
6625 struct extent_map *em;
6626 u64 start = extent_key->objectid - offset;
6627 u64 end = start + extent_key->offset - 1;
6628
6629 em = alloc_extent_map(GFP_NOFS);
6630 BUG_ON(!em);
6631
6632 em->start = start;
6633 em->len = extent_key->offset;
6634 em->block_len = extent_key->offset;
6635 em->block_start = extent_key->objectid;
6636 em->bdev = root->fs_info->fs_devices->latest_bdev;
6637 set_bit(EXTENT_FLAG_PINNED, &em->flags);
6638
6639 /* setup extent map to cheat btrfs_readpage */
6640 lock_extent(&BTRFS_I(reloc_inode)->io_tree, start, end, GFP_NOFS);
6641 while (1) {
6642 int ret;
6643 write_lock(&em_tree->lock);
6644 ret = add_extent_mapping(em_tree, em);
6645 write_unlock(&em_tree->lock);
6646 if (ret != -EEXIST) {
6647 free_extent_map(em);
6648 break;
6649 }
6650 btrfs_drop_extent_cache(reloc_inode, start, end, 0);
6651 }
6652 unlock_extent(&BTRFS_I(reloc_inode)->io_tree, start, end, GFP_NOFS);
6653
6654 return relocate_inode_pages(reloc_inode, start, extent_key->offset);
6655 }
6656
6657 struct btrfs_ref_path {
6658 u64 extent_start;
6659 u64 nodes[BTRFS_MAX_LEVEL];
6660 u64 root_objectid;
6661 u64 root_generation;
6662 u64 owner_objectid;
6663 u32 num_refs;
6664 int lowest_level;
6665 int current_level;
6666 int shared_level;
6667
6668 struct btrfs_key node_keys[BTRFS_MAX_LEVEL];
6669 u64 new_nodes[BTRFS_MAX_LEVEL];
6670 };
6671
6672 struct disk_extent {
6673 u64 ram_bytes;
6674 u64 disk_bytenr;
6675 u64 disk_num_bytes;
6676 u64 offset;
6677 u64 num_bytes;
6678 u8 compression;
6679 u8 encryption;
6680 u16 other_encoding;
6681 };
6682
6683 static int is_cowonly_root(u64 root_objectid)
6684 {
6685 if (root_objectid == BTRFS_ROOT_TREE_OBJECTID ||
6686 root_objectid == BTRFS_EXTENT_TREE_OBJECTID ||
6687 root_objectid == BTRFS_CHUNK_TREE_OBJECTID ||
6688 root_objectid == BTRFS_DEV_TREE_OBJECTID ||
6689 root_objectid == BTRFS_TREE_LOG_OBJECTID ||
6690 root_objectid == BTRFS_CSUM_TREE_OBJECTID)
6691 return 1;
6692 return 0;
6693 }
6694
6695 static noinline int __next_ref_path(struct btrfs_trans_handle *trans,
6696 struct btrfs_root *extent_root,
6697 struct btrfs_ref_path *ref_path,
6698 int first_time)
6699 {
6700 struct extent_buffer *leaf;
6701 struct btrfs_path *path;
6702 struct btrfs_extent_ref *ref;
6703 struct btrfs_key key;
6704 struct btrfs_key found_key;
6705 u64 bytenr;
6706 u32 nritems;
6707 int level;
6708 int ret = 1;
6709
6710 path = btrfs_alloc_path();
6711 if (!path)
6712 return -ENOMEM;
6713
6714 if (first_time) {
6715 ref_path->lowest_level = -1;
6716 ref_path->current_level = -1;
6717 ref_path->shared_level = -1;
6718 goto walk_up;
6719 }
6720 walk_down:
6721 level = ref_path->current_level - 1;
6722 while (level >= -1) {
6723 u64 parent;
6724 if (level < ref_path->lowest_level)
6725 break;
6726
6727 if (level >= 0)
6728 bytenr = ref_path->nodes[level];
6729 else
6730 bytenr = ref_path->extent_start;
6731 BUG_ON(bytenr == 0);
6732
6733 parent = ref_path->nodes[level + 1];
6734 ref_path->nodes[level + 1] = 0;
6735 ref_path->current_level = level;
6736 BUG_ON(parent == 0);
6737
6738 key.objectid = bytenr;
6739 key.offset = parent + 1;
6740 key.type = BTRFS_EXTENT_REF_KEY;
6741
6742 ret = btrfs_search_slot(trans, extent_root, &key, path, 0, 0);
6743 if (ret < 0)
6744 goto out;
6745 BUG_ON(ret == 0);
6746
6747 leaf = path->nodes[0];
6748 nritems = btrfs_header_nritems(leaf);
6749 if (path->slots[0] >= nritems) {
6750 ret = btrfs_next_leaf(extent_root, path);
6751 if (ret < 0)
6752 goto out;
6753 if (ret > 0)
6754 goto next;
6755 leaf = path->nodes[0];
6756 }
6757
6758 btrfs_item_key_to_cpu(leaf, &found_key, path->slots[0]);
6759 if (found_key.objectid == bytenr &&
6760 found_key.type == BTRFS_EXTENT_REF_KEY) {
6761 if (level < ref_path->shared_level)
6762 ref_path->shared_level = level;
6763 goto found;
6764 }
6765 next:
6766 level--;
6767 btrfs_release_path(extent_root, path);
6768 cond_resched();
6769 }
6770 /* reached lowest level */
6771 ret = 1;
6772 goto out;
6773 walk_up:
6774 level = ref_path->current_level;
6775 while (level < BTRFS_MAX_LEVEL - 1) {
6776 u64 ref_objectid;
6777
6778 if (level >= 0)
6779 bytenr = ref_path->nodes[level];
6780 else
6781 bytenr = ref_path->extent_start;
6782
6783 BUG_ON(bytenr == 0);
6784
6785 key.objectid = bytenr;
6786 key.offset = 0;
6787 key.type = BTRFS_EXTENT_REF_KEY;
6788
6789 ret = btrfs_search_slot(trans, extent_root, &key, path, 0, 0);
6790 if (ret < 0)
6791 goto out;
6792
6793 leaf = path->nodes[0];
6794 nritems = btrfs_header_nritems(leaf);
6795 if (path->slots[0] >= nritems) {
6796 ret = btrfs_next_leaf(extent_root, path);
6797 if (ret < 0)
6798 goto out;
6799 if (ret > 0) {
6800 /* the extent was freed by someone */
6801 if (ref_path->lowest_level == level)
6802 goto out;
6803 btrfs_release_path(extent_root, path);
6804 goto walk_down;
6805 }
6806 leaf = path->nodes[0];
6807 }
6808
6809 btrfs_item_key_to_cpu(leaf, &found_key, path->slots[0]);
6810 if (found_key.objectid != bytenr ||
6811 found_key.type != BTRFS_EXTENT_REF_KEY) {
6812 /* the extent was freed by someone */
6813 if (ref_path->lowest_level == level) {
6814 ret = 1;
6815 goto out;
6816 }
6817 btrfs_release_path(extent_root, path);
6818 goto walk_down;
6819 }
6820 found:
6821 ref = btrfs_item_ptr(leaf, path->slots[0],
6822 struct btrfs_extent_ref);
6823 ref_objectid = btrfs_ref_objectid(leaf, ref);
6824 if (ref_objectid < BTRFS_FIRST_FREE_OBJECTID) {
6825 if (first_time) {
6826 level = (int)ref_objectid;
6827 BUG_ON(level >= BTRFS_MAX_LEVEL);
6828 ref_path->lowest_level = level;
6829 ref_path->current_level = level;
6830 ref_path->nodes[level] = bytenr;
6831 } else {
6832 WARN_ON(ref_objectid != level);
6833 }
6834 } else {
6835 WARN_ON(level != -1);
6836 }
6837 first_time = 0;
6838
6839 if (ref_path->lowest_level == level) {
6840 ref_path->owner_objectid = ref_objectid;
6841 ref_path->num_refs = btrfs_ref_num_refs(leaf, ref);
6842 }
6843
6844 /*
6845 * the block is tree root or the block isn't in reference
6846 * counted tree.
6847 */
6848 if (found_key.objectid == found_key.offset ||
6849 is_cowonly_root(btrfs_ref_root(leaf, ref))) {
6850 ref_path->root_objectid = btrfs_ref_root(leaf, ref);
6851 ref_path->root_generation =
6852 btrfs_ref_generation(leaf, ref);
6853 if (level < 0) {
6854 /* special reference from the tree log */
6855 ref_path->nodes[0] = found_key.offset;
6856 ref_path->current_level = 0;
6857 }
6858 ret = 0;
6859 goto out;
6860 }
6861
6862 level++;
6863 BUG_ON(ref_path->nodes[level] != 0);
6864 ref_path->nodes[level] = found_key.offset;
6865 ref_path->current_level = level;
6866
6867 /*
6868 * the reference was created in the running transaction,
6869 * no need to continue walking up.
6870 */
6871 if (btrfs_ref_generation(leaf, ref) == trans->transid) {
6872 ref_path->root_objectid = btrfs_ref_root(leaf, ref);
6873 ref_path->root_generation =
6874 btrfs_ref_generation(leaf, ref);
6875 ret = 0;
6876 goto out;
6877 }
6878
6879 btrfs_release_path(extent_root, path);
6880 cond_resched();
6881 }
6882 /* reached max tree level, but no tree root found. */
6883 BUG();
6884 out:
6885 btrfs_free_path(path);
6886 return ret;
6887 }
6888
6889 static int btrfs_first_ref_path(struct btrfs_trans_handle *trans,
6890 struct btrfs_root *extent_root,
6891 struct btrfs_ref_path *ref_path,
6892 u64 extent_start)
6893 {
6894 memset(ref_path, 0, sizeof(*ref_path));
6895 ref_path->extent_start = extent_start;
6896
6897 return __next_ref_path(trans, extent_root, ref_path, 1);
6898 }
6899
6900 static int btrfs_next_ref_path(struct btrfs_trans_handle *trans,
6901 struct btrfs_root *extent_root,
6902 struct btrfs_ref_path *ref_path)
6903 {
6904 return __next_ref_path(trans, extent_root, ref_path, 0);
6905 }
6906
6907 static noinline int get_new_locations(struct inode *reloc_inode,
6908 struct btrfs_key *extent_key,
6909 u64 offset, int no_fragment,
6910 struct disk_extent **extents,
6911 int *nr_extents)
6912 {
6913 struct btrfs_root *root = BTRFS_I(reloc_inode)->root;
6914 struct btrfs_path *path;
6915 struct btrfs_file_extent_item *fi;
6916 struct extent_buffer *leaf;
6917 struct disk_extent *exts = *extents;
6918 struct btrfs_key found_key;
6919 u64 cur_pos;
6920 u64 last_byte;
6921 u32 nritems;
6922 int nr = 0;
6923 int max = *nr_extents;
6924 int ret;
6925
6926 WARN_ON(!no_fragment && *extents);
6927 if (!exts) {
6928 max = 1;
6929 exts = kmalloc(sizeof(*exts) * max, GFP_NOFS);
6930 if (!exts)
6931 return -ENOMEM;
6932 }
6933
6934 path = btrfs_alloc_path();
6935 if (!path) {
6936 if (exts != *extents)
6937 kfree(exts);
6938 return -ENOMEM;
6939 }
6940
6941 cur_pos = extent_key->objectid - offset;
6942 last_byte = extent_key->objectid + extent_key->offset;
6943 ret = btrfs_lookup_file_extent(NULL, root, path, reloc_inode->i_ino,
6944 cur_pos, 0);
6945 if (ret < 0)
6946 goto out;
6947 if (ret > 0) {
6948 ret = -ENOENT;
6949 goto out;
6950 }
6951
6952 while (1) {
6953 leaf = path->nodes[0];
6954 nritems = btrfs_header_nritems(leaf);
6955 if (path->slots[0] >= nritems) {
6956 ret = btrfs_next_leaf(root, path);
6957 if (ret < 0)
6958 goto out;
6959 if (ret > 0)
6960 break;
6961 leaf = path->nodes[0];
6962 }
6963
6964 btrfs_item_key_to_cpu(leaf, &found_key, path->slots[0]);
6965 if (found_key.offset != cur_pos ||
6966 found_key.type != BTRFS_EXTENT_DATA_KEY ||
6967 found_key.objectid != reloc_inode->i_ino)
6968 break;
6969
6970 fi = btrfs_item_ptr(leaf, path->slots[0],
6971 struct btrfs_file_extent_item);
6972 if (btrfs_file_extent_type(leaf, fi) !=
6973 BTRFS_FILE_EXTENT_REG ||
6974 btrfs_file_extent_disk_bytenr(leaf, fi) == 0)
6975 break;
6976
6977 if (nr == max) {
6978 struct disk_extent *old = exts;
6979 max *= 2;
6980 exts = kzalloc(sizeof(*exts) * max, GFP_NOFS);
6981 if (!exts) {
6982 ret = -ENOMEM;
6983 goto out;
6984 }
6985 memcpy(exts, old, sizeof(*exts) * nr);
6986 if (old != *extents)
6987 kfree(old);
6988 }
6989
6990 exts[nr].disk_bytenr =
6991 btrfs_file_extent_disk_bytenr(leaf, fi);
6992 exts[nr].disk_num_bytes =
6993 btrfs_file_extent_disk_num_bytes(leaf, fi);
6994 exts[nr].offset = btrfs_file_extent_offset(leaf, fi);
6995 exts[nr].num_bytes = btrfs_file_extent_num_bytes(leaf, fi);
6996 exts[nr].ram_bytes = btrfs_file_extent_ram_bytes(leaf, fi);
6997 exts[nr].compression = btrfs_file_extent_compression(leaf, fi);
6998 exts[nr].encryption = btrfs_file_extent_encryption(leaf, fi);
6999 exts[nr].other_encoding = btrfs_file_extent_other_encoding(leaf,
7000 fi);
7001 BUG_ON(exts[nr].offset > 0);
7002 BUG_ON(exts[nr].compression || exts[nr].encryption);
7003 BUG_ON(exts[nr].num_bytes != exts[nr].disk_num_bytes);
7004
7005 cur_pos += exts[nr].num_bytes;
7006 nr++;
7007
7008 if (cur_pos + offset >= last_byte)
7009 break;
7010
7011 if (no_fragment) {
7012 ret = 1;
7013 goto out;
7014 }
7015 path->slots[0]++;
7016 }
7017
7018 BUG_ON(cur_pos + offset > last_byte);
7019 if (cur_pos + offset < last_byte) {
7020 ret = -ENOENT;
7021 goto out;
7022 }
7023 ret = 0;
7024 out:
7025 btrfs_free_path(path);
7026 if (ret) {
7027 if (exts != *extents)
7028 kfree(exts);
7029 } else {
7030 *extents = exts;
7031 *nr_extents = nr;
7032 }
7033 return ret;
7034 }
7035
7036 static noinline int replace_one_extent(struct btrfs_trans_handle *trans,
7037 struct btrfs_root *root,
7038 struct btrfs_path *path,
7039 struct btrfs_key *extent_key,
7040 struct btrfs_key *leaf_key,
7041 struct btrfs_ref_path *ref_path,
7042 struct disk_extent *new_extents,
7043 int nr_extents)
7044 {
7045 struct extent_buffer *leaf;
7046 struct btrfs_file_extent_item *fi;
7047 struct inode *inode = NULL;
7048 struct btrfs_key key;
7049 u64 lock_start = 0;
7050 u64 lock_end = 0;
7051 u64 num_bytes;
7052 u64 ext_offset;
7053 u64 search_end = (u64)-1;
7054 u32 nritems;
7055 int nr_scaned = 0;
7056 int extent_locked = 0;
7057 int extent_type;
7058 int ret;
7059
7060 memcpy(&key, leaf_key, sizeof(key));
7061 if (ref_path->owner_objectid != BTRFS_MULTIPLE_OBJECTIDS) {
7062 if (key.objectid < ref_path->owner_objectid ||
7063 (key.objectid == ref_path->owner_objectid &&
7064 key.type < BTRFS_EXTENT_DATA_KEY)) {
7065 key.objectid = ref_path->owner_objectid;
7066 key.type = BTRFS_EXTENT_DATA_KEY;
7067 key.offset = 0;
7068 }
7069 }
7070
7071 while (1) {
7072 ret = btrfs_search_slot(trans, root, &key, path, 0, 1);
7073 if (ret < 0)
7074 goto out;
7075
7076 leaf = path->nodes[0];
7077 nritems = btrfs_header_nritems(leaf);
7078 next:
7079 if (extent_locked && ret > 0) {
7080 /*
7081 * the file extent item was modified by someone
7082 * before the extent got locked.
7083 */
7084 unlock_extent(&BTRFS_I(inode)->io_tree, lock_start,
7085 lock_end, GFP_NOFS);
7086 extent_locked = 0;
7087 }
7088
7089 if (path->slots[0] >= nritems) {
7090 if (++nr_scaned > 2)
7091 break;
7092
7093 BUG_ON(extent_locked);
7094 ret = btrfs_next_leaf(root, path);
7095 if (ret < 0)
7096 goto out;
7097 if (ret > 0)
7098 break;
7099 leaf = path->nodes[0];
7100 nritems = btrfs_header_nritems(leaf);
7101 }
7102
7103 btrfs_item_key_to_cpu(leaf, &key, path->slots[0]);
7104
7105 if (ref_path->owner_objectid != BTRFS_MULTIPLE_OBJECTIDS) {
7106 if ((key.objectid > ref_path->owner_objectid) ||
7107 (key.objectid == ref_path->owner_objectid &&
7108 key.type > BTRFS_EXTENT_DATA_KEY) ||
7109 key.offset >= search_end)
7110 break;
7111 }
7112
7113 if (inode && key.objectid != inode->i_ino) {
7114 BUG_ON(extent_locked);
7115 btrfs_release_path(root, path);
7116 mutex_unlock(&inode->i_mutex);
7117 iput(inode);
7118 inode = NULL;
7119 continue;
7120 }
7121
7122 if (key.type != BTRFS_EXTENT_DATA_KEY) {
7123 path->slots[0]++;
7124 ret = 1;
7125 goto next;
7126 }
7127 fi = btrfs_item_ptr(leaf, path->slots[0],
7128 struct btrfs_file_extent_item);
7129 extent_type = btrfs_file_extent_type(leaf, fi);
7130 if ((extent_type != BTRFS_FILE_EXTENT_REG &&
7131 extent_type != BTRFS_FILE_EXTENT_PREALLOC) ||
7132 (btrfs_file_extent_disk_bytenr(leaf, fi) !=
7133 extent_key->objectid)) {
7134 path->slots[0]++;
7135 ret = 1;
7136 goto next;
7137 }
7138
7139 num_bytes = btrfs_file_extent_num_bytes(leaf, fi);
7140 ext_offset = btrfs_file_extent_offset(leaf, fi);
7141
7142 if (search_end == (u64)-1) {
7143 search_end = key.offset - ext_offset +
7144 btrfs_file_extent_ram_bytes(leaf, fi);
7145 }
7146
7147 if (!extent_locked) {
7148 lock_start = key.offset;
7149 lock_end = lock_start + num_bytes - 1;
7150 } else {
7151 if (lock_start > key.offset ||
7152 lock_end + 1 < key.offset + num_bytes) {
7153 unlock_extent(&BTRFS_I(inode)->io_tree,
7154 lock_start, lock_end, GFP_NOFS);
7155 extent_locked = 0;
7156 }
7157 }
7158
7159 if (!inode) {
7160 btrfs_release_path(root, path);
7161
7162 inode = btrfs_iget_locked(root->fs_info->sb,
7163 key.objectid, root);
7164 if (inode->i_state & I_NEW) {
7165 BTRFS_I(inode)->root = root;
7166 BTRFS_I(inode)->location.objectid =
7167 key.objectid;
7168 BTRFS_I(inode)->location.type =
7169 BTRFS_INODE_ITEM_KEY;
7170 BTRFS_I(inode)->location.offset = 0;
7171 btrfs_read_locked_inode(inode);
7172 unlock_new_inode(inode);
7173 }
7174 /*
7175 * some code call btrfs_commit_transaction while
7176 * holding the i_mutex, so we can't use mutex_lock
7177 * here.
7178 */
7179 if (is_bad_inode(inode) ||
7180 !mutex_trylock(&inode->i_mutex)) {
7181 iput(inode);
7182 inode = NULL;
7183 key.offset = (u64)-1;
7184 goto skip;
7185 }
7186 }
7187
7188 if (!extent_locked) {
7189 struct btrfs_ordered_extent *ordered;
7190
7191 btrfs_release_path(root, path);
7192
7193 lock_extent(&BTRFS_I(inode)->io_tree, lock_start,
7194 lock_end, GFP_NOFS);
7195 ordered = btrfs_lookup_first_ordered_extent(inode,
7196 lock_end);
7197 if (ordered &&
7198 ordered->file_offset <= lock_end &&
7199 ordered->file_offset + ordered->len > lock_start) {
7200 unlock_extent(&BTRFS_I(inode)->io_tree,
7201 lock_start, lock_end, GFP_NOFS);
7202 btrfs_start_ordered_extent(inode, ordered, 1);
7203 btrfs_put_ordered_extent(ordered);
7204 key.offset += num_bytes;
7205 goto skip;
7206 }
7207 if (ordered)
7208 btrfs_put_ordered_extent(ordered);
7209
7210 extent_locked = 1;
7211 continue;
7212 }
7213
7214 if (nr_extents == 1) {
7215 /* update extent pointer in place */
7216 btrfs_set_file_extent_disk_bytenr(leaf, fi,
7217 new_extents[0].disk_bytenr);
7218 btrfs_set_file_extent_disk_num_bytes(leaf, fi,
7219 new_extents[0].disk_num_bytes);
7220 btrfs_mark_buffer_dirty(leaf);
7221
7222 btrfs_drop_extent_cache(inode, key.offset,
7223 key.offset + num_bytes - 1, 0);
7224
7225 ret = btrfs_inc_extent_ref(trans, root,
7226 new_extents[0].disk_bytenr,
7227 new_extents[0].disk_num_bytes,
7228 leaf->start,
7229 root->root_key.objectid,
7230 trans->transid,
7231 key.objectid);
7232 BUG_ON(ret);
7233
7234 ret = btrfs_free_extent(trans, root,
7235 extent_key->objectid,
7236 extent_key->offset,
7237 leaf->start,
7238 btrfs_header_owner(leaf),
7239 btrfs_header_generation(leaf),
7240 key.objectid, 0);
7241 BUG_ON(ret);
7242
7243 btrfs_release_path(root, path);
7244 key.offset += num_bytes;
7245 } else {
7246 BUG_ON(1);
7247 #if 0
7248 u64 alloc_hint;
7249 u64 extent_len;
7250 int i;
7251 /*
7252 * drop old extent pointer at first, then insert the
7253 * new pointers one bye one
7254 */
7255 btrfs_release_path(root, path);
7256 ret = btrfs_drop_extents(trans, root, inode, key.offset,
7257 key.offset + num_bytes,
7258 key.offset, &alloc_hint);
7259 BUG_ON(ret);
7260
7261 for (i = 0; i < nr_extents; i++) {
7262 if (ext_offset >= new_extents[i].num_bytes) {
7263 ext_offset -= new_extents[i].num_bytes;
7264 continue;
7265 }
7266 extent_len = min(new_extents[i].num_bytes -
7267 ext_offset, num_bytes);
7268
7269 ret = btrfs_insert_empty_item(trans, root,
7270 path, &key,
7271 sizeof(*fi));
7272 BUG_ON(ret);
7273
7274 leaf = path->nodes[0];
7275 fi = btrfs_item_ptr(leaf, path->slots[0],
7276 struct btrfs_file_extent_item);
7277 btrfs_set_file_extent_generation(leaf, fi,
7278 trans->transid);
7279 btrfs_set_file_extent_type(leaf, fi,
7280 BTRFS_FILE_EXTENT_REG);
7281 btrfs_set_file_extent_disk_bytenr(leaf, fi,
7282 new_extents[i].disk_bytenr);
7283 btrfs_set_file_extent_disk_num_bytes(leaf, fi,
7284 new_extents[i].disk_num_bytes);
7285 btrfs_set_file_extent_ram_bytes(leaf, fi,
7286 new_extents[i].ram_bytes);
7287
7288 btrfs_set_file_extent_compression(leaf, fi,
7289 new_extents[i].compression);
7290 btrfs_set_file_extent_encryption(leaf, fi,
7291 new_extents[i].encryption);
7292 btrfs_set_file_extent_other_encoding(leaf, fi,
7293 new_extents[i].other_encoding);
7294
7295 btrfs_set_file_extent_num_bytes(leaf, fi,
7296 extent_len);
7297 ext_offset += new_extents[i].offset;
7298 btrfs_set_file_extent_offset(leaf, fi,
7299 ext_offset);
7300 btrfs_mark_buffer_dirty(leaf);
7301
7302 btrfs_drop_extent_cache(inode, key.offset,
7303 key.offset + extent_len - 1, 0);
7304
7305 ret = btrfs_inc_extent_ref(trans, root,
7306 new_extents[i].disk_bytenr,
7307 new_extents[i].disk_num_bytes,
7308 leaf->start,
7309 root->root_key.objectid,
7310 trans->transid, key.objectid);
7311 BUG_ON(ret);
7312 btrfs_release_path(root, path);
7313
7314 inode_add_bytes(inode, extent_len);
7315
7316 ext_offset = 0;
7317 num_bytes -= extent_len;
7318 key.offset += extent_len;
7319
7320 if (num_bytes == 0)
7321 break;
7322 }
7323 BUG_ON(i >= nr_extents);
7324 #endif
7325 }
7326
7327 if (extent_locked) {
7328 unlock_extent(&BTRFS_I(inode)->io_tree, lock_start,
7329 lock_end, GFP_NOFS);
7330 extent_locked = 0;
7331 }
7332 skip:
7333 if (ref_path->owner_objectid != BTRFS_MULTIPLE_OBJECTIDS &&
7334 key.offset >= search_end)
7335 break;
7336
7337 cond_resched();
7338 }
7339 ret = 0;
7340 out:
7341 btrfs_release_path(root, path);
7342 if (inode) {
7343 mutex_unlock(&inode->i_mutex);
7344 if (extent_locked) {
7345 unlock_extent(&BTRFS_I(inode)->io_tree, lock_start,
7346 lock_end, GFP_NOFS);
7347 }
7348 iput(inode);
7349 }
7350 return ret;
7351 }
7352
7353 int btrfs_reloc_tree_cache_ref(struct btrfs_trans_handle *trans,
7354 struct btrfs_root *root,
7355 struct extent_buffer *buf, u64 orig_start)
7356 {
7357 int level;
7358 int ret;
7359
7360 BUG_ON(btrfs_header_generation(buf) != trans->transid);
7361 BUG_ON(root->root_key.objectid != BTRFS_TREE_RELOC_OBJECTID);
7362
7363 level = btrfs_header_level(buf);
7364 if (level == 0) {
7365 struct btrfs_leaf_ref *ref;
7366 struct btrfs_leaf_ref *orig_ref;
7367
7368 orig_ref = btrfs_lookup_leaf_ref(root, orig_start);
7369 if (!orig_ref)
7370 return -ENOENT;
7371
7372 ref = btrfs_alloc_leaf_ref(root, orig_ref->nritems);
7373 if (!ref) {
7374 btrfs_free_leaf_ref(root, orig_ref);
7375 return -ENOMEM;
7376 }
7377
7378 ref->nritems = orig_ref->nritems;
7379 memcpy(ref->extents, orig_ref->extents,
7380 sizeof(ref->extents[0]) * ref->nritems);
7381
7382 btrfs_free_leaf_ref(root, orig_ref);
7383
7384 ref->root_gen = trans->transid;
7385 ref->bytenr = buf->start;
7386 ref->owner = btrfs_header_owner(buf);
7387 ref->generation = btrfs_header_generation(buf);
7388
7389 ret = btrfs_add_leaf_ref(root, ref, 0);
7390 WARN_ON(ret);
7391 btrfs_free_leaf_ref(root, ref);
7392 }
7393 return 0;
7394 }
7395
7396 static noinline int invalidate_extent_cache(struct btrfs_root *root,
7397 struct extent_buffer *leaf,
7398 struct btrfs_block_group_cache *group,
7399 struct btrfs_root *target_root)
7400 {
7401 struct btrfs_key key;
7402 struct inode *inode = NULL;
7403 struct btrfs_file_extent_item *fi;
7404 struct extent_state *cached_state = NULL;
7405 u64 num_bytes;
7406 u64 skip_objectid = 0;
7407 u32 nritems;
7408 u32 i;
7409
7410 nritems = btrfs_header_nritems(leaf);
7411 for (i = 0; i < nritems; i++) {
7412 btrfs_item_key_to_cpu(leaf, &key, i);
7413 if (key.objectid == skip_objectid ||
7414 key.type != BTRFS_EXTENT_DATA_KEY)
7415 continue;
7416 fi = btrfs_item_ptr(leaf, i, struct btrfs_file_extent_item);
7417 if (btrfs_file_extent_type(leaf, fi) ==
7418 BTRFS_FILE_EXTENT_INLINE)
7419 continue;
7420 if (btrfs_file_extent_disk_bytenr(leaf, fi) == 0)
7421 continue;
7422 if (!inode || inode->i_ino != key.objectid) {
7423 iput(inode);
7424 inode = btrfs_ilookup(target_root->fs_info->sb,
7425 key.objectid, target_root, 1);
7426 }
7427 if (!inode) {
7428 skip_objectid = key.objectid;
7429 continue;
7430 }
7431 num_bytes = btrfs_file_extent_num_bytes(leaf, fi);
7432
7433 lock_extent_bits(&BTRFS_I(inode)->io_tree, key.offset,
7434 key.offset + num_bytes - 1, 0, &cached_state,
7435 GFP_NOFS);
7436 btrfs_drop_extent_cache(inode, key.offset,
7437 key.offset + num_bytes - 1, 1);
7438 unlock_extent_cached(&BTRFS_I(inode)->io_tree, key.offset,
7439 key.offset + num_bytes - 1, &cached_state,
7440 GFP_NOFS);
7441 cond_resched();
7442 }
7443 iput(inode);
7444 return 0;
7445 }
7446
7447 static noinline int replace_extents_in_leaf(struct btrfs_trans_handle *trans,
7448 struct btrfs_root *root,
7449 struct extent_buffer *leaf,
7450 struct btrfs_block_group_cache *group,
7451 struct inode *reloc_inode)
7452 {
7453 struct btrfs_key key;
7454 struct btrfs_key extent_key;
7455 struct btrfs_file_extent_item *fi;
7456 struct btrfs_leaf_ref *ref;
7457 struct disk_extent *new_extent;
7458 u64 bytenr;
7459 u64 num_bytes;
7460 u32 nritems;
7461 u32 i;
7462 int ext_index;
7463 int nr_extent;
7464 int ret;
7465
7466 new_extent = kmalloc(sizeof(*new_extent), GFP_NOFS);
7467 if (!new_extent)
7468 return -ENOMEM;
7469
7470 ref = btrfs_lookup_leaf_ref(root, leaf->start);
7471 BUG_ON(!ref);
7472
7473 ext_index = -1;
7474 nritems = btrfs_header_nritems(leaf);
7475 for (i = 0; i < nritems; i++) {
7476 btrfs_item_key_to_cpu(leaf, &key, i);
7477 if (btrfs_key_type(&key) != BTRFS_EXTENT_DATA_KEY)
7478 continue;
7479 fi = btrfs_item_ptr(leaf, i, struct btrfs_file_extent_item);
7480 if (btrfs_file_extent_type(leaf, fi) ==
7481 BTRFS_FILE_EXTENT_INLINE)
7482 continue;
7483 bytenr = btrfs_file_extent_disk_bytenr(leaf, fi);
7484 num_bytes = btrfs_file_extent_disk_num_bytes(leaf, fi);
7485 if (bytenr == 0)
7486 continue;
7487
7488 ext_index++;
7489 if (bytenr >= group->key.objectid + group->key.offset ||
7490 bytenr + num_bytes <= group->key.objectid)
7491 continue;
7492
7493 extent_key.objectid = bytenr;
7494 extent_key.offset = num_bytes;
7495 extent_key.type = BTRFS_EXTENT_ITEM_KEY;
7496 nr_extent = 1;
7497 ret = get_new_locations(reloc_inode, &extent_key,
7498 group->key.objectid, 1,
7499 &new_extent, &nr_extent);
7500 if (ret > 0)
7501 continue;
7502 BUG_ON(ret < 0);
7503
7504 BUG_ON(ref->extents[ext_index].bytenr != bytenr);
7505 BUG_ON(ref->extents[ext_index].num_bytes != num_bytes);
7506 ref->extents[ext_index].bytenr = new_extent->disk_bytenr;
7507 ref->extents[ext_index].num_bytes = new_extent->disk_num_bytes;
7508
7509 btrfs_set_file_extent_disk_bytenr(leaf, fi,
7510 new_extent->disk_bytenr);
7511 btrfs_set_file_extent_disk_num_bytes(leaf, fi,
7512 new_extent->disk_num_bytes);
7513 btrfs_mark_buffer_dirty(leaf);
7514
7515 ret = btrfs_inc_extent_ref(trans, root,
7516 new_extent->disk_bytenr,
7517 new_extent->disk_num_bytes,
7518 leaf->start,
7519 root->root_key.objectid,
7520 trans->transid, key.objectid);
7521 BUG_ON(ret);
7522
7523 ret = btrfs_free_extent(trans, root,
7524 bytenr, num_bytes, leaf->start,
7525 btrfs_header_owner(leaf),
7526 btrfs_header_generation(leaf),
7527 key.objectid, 0);
7528 BUG_ON(ret);
7529 cond_resched();
7530 }
7531 kfree(new_extent);
7532 BUG_ON(ext_index + 1 != ref->nritems);
7533 btrfs_free_leaf_ref(root, ref);
7534 return 0;
7535 }
7536
7537 int btrfs_free_reloc_root(struct btrfs_trans_handle *trans,
7538 struct btrfs_root *root)
7539 {
7540 struct btrfs_root *reloc_root;
7541 int ret;
7542
7543 if (root->reloc_root) {
7544 reloc_root = root->reloc_root;
7545 root->reloc_root = NULL;
7546 list_add(&reloc_root->dead_list,
7547 &root->fs_info->dead_reloc_roots);
7548
7549 btrfs_set_root_bytenr(&reloc_root->root_item,
7550 reloc_root->node->start);
7551 btrfs_set_root_level(&root->root_item,
7552 btrfs_header_level(reloc_root->node));
7553 memset(&reloc_root->root_item.drop_progress, 0,
7554 sizeof(struct btrfs_disk_key));
7555 reloc_root->root_item.drop_level = 0;
7556
7557 ret = btrfs_update_root(trans, root->fs_info->tree_root,
7558 &reloc_root->root_key,
7559 &reloc_root->root_item);
7560 BUG_ON(ret);
7561 }
7562 return 0;
7563 }
7564
7565 int btrfs_drop_dead_reloc_roots(struct btrfs_root *root)
7566 {
7567 struct btrfs_trans_handle *trans;
7568 struct btrfs_root *reloc_root;
7569 struct btrfs_root *prev_root = NULL;
7570 struct list_head dead_roots;
7571 int ret;
7572 unsigned long nr;
7573
7574 INIT_LIST_HEAD(&dead_roots);
7575 list_splice_init(&root->fs_info->dead_reloc_roots, &dead_roots);
7576
7577 while (!list_empty(&dead_roots)) {
7578 reloc_root = list_entry(dead_roots.prev,
7579 struct btrfs_root, dead_list);
7580 list_del_init(&reloc_root->dead_list);
7581
7582 BUG_ON(reloc_root->commit_root != NULL);
7583 while (1) {
7584 trans = btrfs_join_transaction(root, 1);
7585 BUG_ON(IS_ERR(trans));
7586
7587 mutex_lock(&root->fs_info->drop_mutex);
7588 ret = btrfs_drop_snapshot(trans, reloc_root);
7589 if (ret != -EAGAIN)
7590 break;
7591 mutex_unlock(&root->fs_info->drop_mutex);
7592
7593 nr = trans->blocks_used;
7594 ret = btrfs_end_transaction(trans, root);
7595 BUG_ON(ret);
7596 btrfs_btree_balance_dirty(root, nr);
7597 }
7598
7599 free_extent_buffer(reloc_root->node);
7600
7601 ret = btrfs_del_root(trans, root->fs_info->tree_root,
7602 &reloc_root->root_key);
7603 BUG_ON(ret);
7604 mutex_unlock(&root->fs_info->drop_mutex);
7605
7606 nr = trans->blocks_used;
7607 ret = btrfs_end_transaction(trans, root);
7608 BUG_ON(ret);
7609 btrfs_btree_balance_dirty(root, nr);
7610
7611 kfree(prev_root);
7612 prev_root = reloc_root;
7613 }
7614 if (prev_root) {
7615 btrfs_remove_leaf_refs(prev_root, (u64)-1, 0);
7616 kfree(prev_root);
7617 }
7618 return 0;
7619 }
7620
7621 int btrfs_add_dead_reloc_root(struct btrfs_root *root)
7622 {
7623 list_add(&root->dead_list, &root->fs_info->dead_reloc_roots);
7624 return 0;
7625 }
7626
7627 int btrfs_cleanup_reloc_trees(struct btrfs_root *root)
7628 {
7629 struct btrfs_root *reloc_root;
7630 struct btrfs_trans_handle *trans;
7631 struct btrfs_key location;
7632 int found;
7633 int ret;
7634
7635 mutex_lock(&root->fs_info->tree_reloc_mutex);
7636 ret = btrfs_find_dead_roots(root, BTRFS_TREE_RELOC_OBJECTID, NULL);
7637 BUG_ON(ret);
7638 found = !list_empty(&root->fs_info->dead_reloc_roots);
7639 mutex_unlock(&root->fs_info->tree_reloc_mutex);
7640
7641 if (found) {
7642 trans = btrfs_start_transaction(root, 1);
7643 BUG_ON(IS_ERR(trans));
7644 ret = btrfs_commit_transaction(trans, root);
7645 BUG_ON(ret);
7646 }
7647
7648 location.objectid = BTRFS_DATA_RELOC_TREE_OBJECTID;
7649 location.offset = (u64)-1;
7650 location.type = BTRFS_ROOT_ITEM_KEY;
7651
7652 reloc_root = btrfs_read_fs_root_no_name(root->fs_info, &location);
7653 BUG_ON(!reloc_root);
7654 ret = btrfs_orphan_cleanup(reloc_root);
7655 BUG_ON(ret);
7656 return 0;
7657 }
7658
7659 static noinline int init_reloc_tree(struct btrfs_trans_handle *trans,
7660 struct btrfs_root *root)
7661 {
7662 struct btrfs_root *reloc_root;
7663 struct extent_buffer *eb;
7664 struct btrfs_root_item *root_item;
7665 struct btrfs_key root_key;
7666 int ret;
7667
7668 BUG_ON(!root->ref_cows);
7669 if (root->reloc_root)
7670 return 0;
7671
7672 root_item = kmalloc(sizeof(*root_item), GFP_NOFS);
7673 if (!root_item)
7674 return -ENOMEM;
7675
7676 ret = btrfs_copy_root(trans, root, root->commit_root,
7677 &eb, BTRFS_TREE_RELOC_OBJECTID);
7678 BUG_ON(ret);
7679
7680 root_key.objectid = BTRFS_TREE_RELOC_OBJECTID;
7681 root_key.offset = root->root_key.objectid;
7682 root_key.type = BTRFS_ROOT_ITEM_KEY;
7683
7684 memcpy(root_item, &root->root_item, sizeof(root_item));
7685 btrfs_set_root_refs(root_item, 0);
7686 btrfs_set_root_bytenr(root_item, eb->start);
7687 btrfs_set_root_level(root_item, btrfs_header_level(eb));
7688 btrfs_set_root_generation(root_item, trans->transid);
7689
7690 btrfs_tree_unlock(eb);
7691 free_extent_buffer(eb);
7692
7693 ret = btrfs_insert_root(trans, root->fs_info->tree_root,
7694 &root_key, root_item);
7695 BUG_ON(ret);
7696 kfree(root_item);
7697
7698 reloc_root = btrfs_read_fs_root_no_radix(root->fs_info->tree_root,
7699 &root_key);
7700 BUG_ON(IS_ERR(reloc_root));
7701 reloc_root->last_trans = trans->transid;
7702 reloc_root->commit_root = NULL;
7703 reloc_root->ref_tree = &root->fs_info->reloc_ref_tree;
7704
7705 root->reloc_root = reloc_root;
7706 return 0;
7707 }
7708
7709 /*
7710 * Core function of space balance.
7711 *
7712 * The idea is using reloc trees to relocate tree blocks in reference
7713 * counted roots. There is one reloc tree for each subvol, and all
7714 * reloc trees share same root key objectid. Reloc trees are snapshots
7715 * of the latest committed roots of subvols (root->commit_root).
7716 *
7717 * To relocate a tree block referenced by a subvol, there are two steps.
7718 * COW the block through subvol's reloc tree, then update block pointer
7719 * in the subvol to point to the new block. Since all reloc trees share
7720 * same root key objectid, doing special handing for tree blocks owned
7721 * by them is easy. Once a tree block has been COWed in one reloc tree,
7722 * we can use the resulting new block directly when the same block is
7723 * required to COW again through other reloc trees. By this way, relocated
7724 * tree blocks are shared between reloc trees, so they are also shared
7725 * between subvols.
7726 */
7727 static noinline int relocate_one_path(struct btrfs_trans_handle *trans,
7728 struct btrfs_root *root,
7729 struct btrfs_path *path,
7730 struct btrfs_key *first_key,
7731 struct btrfs_ref_path *ref_path,
7732 struct btrfs_block_group_cache *group,
7733 struct inode *reloc_inode)
7734 {
7735 struct btrfs_root *reloc_root;
7736 struct extent_buffer *eb = NULL;
7737 struct btrfs_key *keys;
7738 u64 *nodes;
7739 int level;
7740 int shared_level;
7741 int lowest_level = 0;
7742 int ret;
7743
7744 if (ref_path->owner_objectid < BTRFS_FIRST_FREE_OBJECTID)
7745 lowest_level = ref_path->owner_objectid;
7746
7747 if (!root->ref_cows) {
7748 path->lowest_level = lowest_level;
7749 ret = btrfs_search_slot(trans, root, first_key, path, 0, 1);
7750 BUG_ON(ret < 0);
7751 path->lowest_level = 0;
7752 btrfs_release_path(root, path);
7753 return 0;
7754 }
7755
7756 mutex_lock(&root->fs_info->tree_reloc_mutex);
7757 ret = init_reloc_tree(trans, root);
7758 BUG_ON(ret);
7759 reloc_root = root->reloc_root;
7760
7761 shared_level = ref_path->shared_level;
7762 ref_path->shared_level = BTRFS_MAX_LEVEL - 1;
7763
7764 keys = ref_path->node_keys;
7765 nodes = ref_path->new_nodes;
7766 memset(&keys[shared_level + 1], 0,
7767 sizeof(*keys) * (BTRFS_MAX_LEVEL - shared_level - 1));
7768 memset(&nodes[shared_level + 1], 0,
7769 sizeof(*nodes) * (BTRFS_MAX_LEVEL - shared_level - 1));
7770
7771 if (nodes[lowest_level] == 0) {
7772 path->lowest_level = lowest_level;
7773 ret = btrfs_search_slot(trans, reloc_root, first_key, path,
7774 0, 1);
7775 BUG_ON(ret);
7776 for (level = lowest_level; level < BTRFS_MAX_LEVEL; level++) {
7777 eb = path->nodes[level];
7778 if (!eb || eb == reloc_root->node)
7779 break;
7780 nodes[level] = eb->start;
7781 if (level == 0)
7782 btrfs_item_key_to_cpu(eb, &keys[level], 0);
7783 else
7784 btrfs_node_key_to_cpu(eb, &keys[level], 0);
7785 }
7786 if (nodes[0] &&
7787 ref_path->owner_objectid >= BTRFS_FIRST_FREE_OBJECTID) {
7788 eb = path->nodes[0];
7789 ret = replace_extents_in_leaf(trans, reloc_root, eb,
7790 group, reloc_inode);
7791 BUG_ON(ret);
7792 }
7793 btrfs_release_path(reloc_root, path);
7794 } else {
7795 ret = btrfs_merge_path(trans, reloc_root, keys, nodes,
7796 lowest_level);
7797 BUG_ON(ret);
7798 }
7799
7800 /*
7801 * replace tree blocks in the fs tree with tree blocks in
7802 * the reloc tree.
7803 */
7804 ret = btrfs_merge_path(trans, root, keys, nodes, lowest_level);
7805 BUG_ON(ret < 0);
7806
7807 if (ref_path->owner_objectid >= BTRFS_FIRST_FREE_OBJECTID) {
7808 ret = btrfs_search_slot(trans, reloc_root, first_key, path,
7809 0, 0);
7810 BUG_ON(ret);
7811 extent_buffer_get(path->nodes[0]);
7812 eb = path->nodes[0];
7813 btrfs_release_path(reloc_root, path);
7814 ret = invalidate_extent_cache(reloc_root, eb, group, root);
7815 BUG_ON(ret);
7816 free_extent_buffer(eb);
7817 }
7818
7819 mutex_unlock(&root->fs_info->tree_reloc_mutex);
7820 path->lowest_level = 0;
7821 return 0;
7822 }
7823
7824 static noinline int relocate_tree_block(struct btrfs_trans_handle *trans,
7825 struct btrfs_root *root,
7826 struct btrfs_path *path,
7827 struct btrfs_key *first_key,
7828 struct btrfs_ref_path *ref_path)
7829 {
7830 int ret;
7831
7832 ret = relocate_one_path(trans, root, path, first_key,
7833 ref_path, NULL, NULL);
7834 BUG_ON(ret);
7835
7836 return 0;
7837 }
7838
7839 static noinline int del_extent_zero(struct btrfs_trans_handle *trans,
7840 struct btrfs_root *extent_root,
7841 struct btrfs_path *path,
7842 struct btrfs_key *extent_key)
7843 {
7844 int ret;
7845
7846 ret = btrfs_search_slot(trans, extent_root, extent_key, path, -1, 1);
7847 if (ret)
7848 goto out;
7849 ret = btrfs_del_item(trans, extent_root, path);
7850 out:
7851 btrfs_release_path(extent_root, path);
7852 return ret;
7853 }
7854
7855 static noinline struct btrfs_root *read_ref_root(struct btrfs_fs_info *fs_info,
7856 struct btrfs_ref_path *ref_path)
7857 {
7858 struct btrfs_key root_key;
7859
7860 root_key.objectid = ref_path->root_objectid;
7861 root_key.type = BTRFS_ROOT_ITEM_KEY;
7862 if (is_cowonly_root(ref_path->root_objectid))
7863 root_key.offset = 0;
7864 else
7865 root_key.offset = (u64)-1;
7866
7867 return btrfs_read_fs_root_no_name(fs_info, &root_key);
7868 }
7869
7870 static noinline int relocate_one_extent(struct btrfs_root *extent_root,
7871 struct btrfs_path *path,
7872 struct btrfs_key *extent_key,
7873 struct btrfs_block_group_cache *group,
7874 struct inode *reloc_inode, int pass)
7875 {
7876 struct btrfs_trans_handle *trans;
7877 struct btrfs_root *found_root;
7878 struct btrfs_ref_path *ref_path = NULL;
7879 struct disk_extent *new_extents = NULL;
7880 int nr_extents = 0;
7881 int loops;
7882 int ret;
7883 int level;
7884 struct btrfs_key first_key;
7885 u64 prev_block = 0;
7886
7887
7888 trans = btrfs_start_transaction(extent_root, 1);
7889 BUG_ON(IS_ERR(trans));
7890
7891 if (extent_key->objectid == 0) {
7892 ret = del_extent_zero(trans, extent_root, path, extent_key);
7893 goto out;
7894 }
7895
7896 ref_path = kmalloc(sizeof(*ref_path), GFP_NOFS);
7897 if (!ref_path) {
7898 ret = -ENOMEM;
7899 goto out;
7900 }
7901
7902 for (loops = 0; ; loops++) {
7903 if (loops == 0) {
7904 ret = btrfs_first_ref_path(trans, extent_root, ref_path,
7905 extent_key->objectid);
7906 } else {
7907 ret = btrfs_next_ref_path(trans, extent_root, ref_path);
7908 }
7909 if (ret < 0)
7910 goto out;
7911 if (ret > 0)
7912 break;
7913
7914 if (ref_path->root_objectid == BTRFS_TREE_LOG_OBJECTID ||
7915 ref_path->root_objectid == BTRFS_TREE_RELOC_OBJECTID)
7916 continue;
7917
7918 found_root = read_ref_root(extent_root->fs_info, ref_path);
7919 BUG_ON(!found_root);
7920 /*
7921 * for reference counted tree, only process reference paths
7922 * rooted at the latest committed root.
7923 */
7924 if (found_root->ref_cows &&
7925 ref_path->root_generation != found_root->root_key.offset)
7926 continue;
7927
7928 if (ref_path->owner_objectid >= BTRFS_FIRST_FREE_OBJECTID) {
7929 if (pass == 0) {
7930 /*
7931 * copy data extents to new locations
7932 */
7933 u64 group_start = group->key.objectid;
7934 ret = relocate_data_extent(reloc_inode,
7935 extent_key,
7936 group_start);
7937 if (ret < 0)
7938 goto out;
7939 break;
7940 }
7941 level = 0;
7942 } else {
7943 level = ref_path->owner_objectid;
7944 }
7945
7946 if (prev_block != ref_path->nodes[level]) {
7947 struct extent_buffer *eb;
7948 u64 block_start = ref_path->nodes[level];
7949 u64 block_size = btrfs_level_size(found_root, level);
7950
7951 eb = read_tree_block(found_root, block_start,
7952 block_size, 0);
7953 if (!eb) {
7954 ret = -EIO;
7955 goto out;
7956 }
7957 btrfs_tree_lock(eb);
7958 BUG_ON(level != btrfs_header_level(eb));
7959
7960 if (level == 0)
7961 btrfs_item_key_to_cpu(eb, &first_key, 0);
7962 else
7963 btrfs_node_key_to_cpu(eb, &first_key, 0);
7964
7965 btrfs_tree_unlock(eb);
7966 free_extent_buffer(eb);
7967 prev_block = block_start;
7968 }
7969
7970 mutex_lock(&extent_root->fs_info->trans_mutex);
7971 btrfs_record_root_in_trans(found_root);
7972 mutex_unlock(&extent_root->fs_info->trans_mutex);
7973 if (ref_path->owner_objectid >= BTRFS_FIRST_FREE_OBJECTID) {
7974 /*
7975 * try to update data extent references while
7976 * keeping metadata shared between snapshots.
7977 */
7978 if (pass == 1) {
7979 ret = relocate_one_path(trans, found_root,
7980 path, &first_key, ref_path,
7981 group, reloc_inode);
7982 if (ret < 0)
7983 goto out;
7984 continue;
7985 }
7986 /*
7987 * use fallback method to process the remaining
7988 * references.
7989 */
7990 if (!new_extents) {
7991 u64 group_start = group->key.objectid;
7992 new_extents = kmalloc(sizeof(*new_extents),
7993 GFP_NOFS);
7994 nr_extents = 1;
7995 ret = get_new_locations(reloc_inode,
7996 extent_key,
7997 group_start, 1,
7998 &new_extents,
7999 &nr_extents);
8000 if (ret)
8001 goto out;
8002 }
8003 ret = replace_one_extent(trans, found_root,
8004 path, extent_key,
8005 &first_key, ref_path,
8006 new_extents, nr_extents);
8007 } else {
8008 ret = relocate_tree_block(trans, found_root, path,
8009 &first_key, ref_path);
8010 }
8011 if (ret < 0)
8012 goto out;
8013 }
8014 ret = 0;
8015 out:
8016 btrfs_end_transaction(trans, extent_root);
8017 kfree(new_extents);
8018 kfree(ref_path);
8019 return ret;
8020 }
8021 #endif
8022
8023 static u64 update_block_group_flags(struct btrfs_root *root, u64 flags)
8024 {
8025 u64 num_devices;
8026 u64 stripped = BTRFS_BLOCK_GROUP_RAID0 |
8027 BTRFS_BLOCK_GROUP_RAID1 | BTRFS_BLOCK_GROUP_RAID10;
8028
8029 /*
8030 * we add in the count of missing devices because we want
8031 * to make sure that any RAID levels on a degraded FS
8032 * continue to be honored.
8033 */
8034 num_devices = root->fs_info->fs_devices->rw_devices +
8035 root->fs_info->fs_devices->missing_devices;
8036
8037 if (num_devices == 1) {
8038 stripped |= BTRFS_BLOCK_GROUP_DUP;
8039 stripped = flags & ~stripped;
8040
8041 /* turn raid0 into single device chunks */
8042 if (flags & BTRFS_BLOCK_GROUP_RAID0)
8043 return stripped;
8044
8045 /* turn mirroring into duplication */
8046 if (flags & (BTRFS_BLOCK_GROUP_RAID1 |
8047 BTRFS_BLOCK_GROUP_RAID10))
8048 return stripped | BTRFS_BLOCK_GROUP_DUP;
8049 return flags;
8050 } else {
8051 /* they already had raid on here, just return */
8052 if (flags & stripped)
8053 return flags;
8054
8055 stripped |= BTRFS_BLOCK_GROUP_DUP;
8056 stripped = flags & ~stripped;
8057
8058 /* switch duplicated blocks with raid1 */
8059 if (flags & BTRFS_BLOCK_GROUP_DUP)
8060 return stripped | BTRFS_BLOCK_GROUP_RAID1;
8061
8062 /* turn single device chunks into raid0 */
8063 return stripped | BTRFS_BLOCK_GROUP_RAID0;
8064 }
8065 return flags;
8066 }
8067
8068 static int set_block_group_ro(struct btrfs_block_group_cache *cache)
8069 {
8070 struct btrfs_space_info *sinfo = cache->space_info;
8071 u64 num_bytes;
8072 int ret = -ENOSPC;
8073
8074 if (cache->ro)
8075 return 0;
8076
8077 spin_lock(&sinfo->lock);
8078 spin_lock(&cache->lock);
8079 num_bytes = cache->key.offset - cache->reserved - cache->pinned -
8080 cache->bytes_super - btrfs_block_group_used(&cache->item);
8081
8082 if (sinfo->bytes_used + sinfo->bytes_reserved + sinfo->bytes_pinned +
8083 sinfo->bytes_may_use + sinfo->bytes_readonly +
8084 cache->reserved_pinned + num_bytes <= sinfo->total_bytes) {
8085 sinfo->bytes_readonly += num_bytes;
8086 sinfo->bytes_reserved += cache->reserved_pinned;
8087 cache->reserved_pinned = 0;
8088 cache->ro = 1;
8089 ret = 0;
8090 }
8091
8092 spin_unlock(&cache->lock);
8093 spin_unlock(&sinfo->lock);
8094 return ret;
8095 }
8096
8097 int btrfs_set_block_group_ro(struct btrfs_root *root,
8098 struct btrfs_block_group_cache *cache)
8099
8100 {
8101 struct btrfs_trans_handle *trans;
8102 u64 alloc_flags;
8103 int ret;
8104
8105 BUG_ON(cache->ro);
8106
8107 trans = btrfs_join_transaction(root, 1);
8108 BUG_ON(IS_ERR(trans));
8109
8110 alloc_flags = update_block_group_flags(root, cache->flags);
8111 if (alloc_flags != cache->flags)
8112 do_chunk_alloc(trans, root, 2 * 1024 * 1024, alloc_flags, 1);
8113
8114 ret = set_block_group_ro(cache);
8115 if (!ret)
8116 goto out;
8117 alloc_flags = get_alloc_profile(root, cache->space_info->flags);
8118 ret = do_chunk_alloc(trans, root, 2 * 1024 * 1024, alloc_flags, 1);
8119 if (ret < 0)
8120 goto out;
8121 ret = set_block_group_ro(cache);
8122 out:
8123 btrfs_end_transaction(trans, root);
8124 return ret;
8125 }
8126
8127 int btrfs_force_chunk_alloc(struct btrfs_trans_handle *trans,
8128 struct btrfs_root *root, u64 type)
8129 {
8130 u64 alloc_flags = get_alloc_profile(root, type);
8131 return do_chunk_alloc(trans, root, 2 * 1024 * 1024, alloc_flags, 1);
8132 }
8133
8134 /*
8135 * helper to account the unused space of all the readonly block group in the
8136 * list. takes mirrors into account.
8137 */
8138 static u64 __btrfs_get_ro_block_group_free_space(struct list_head *groups_list)
8139 {
8140 struct btrfs_block_group_cache *block_group;
8141 u64 free_bytes = 0;
8142 int factor;
8143
8144 list_for_each_entry(block_group, groups_list, list) {
8145 spin_lock(&block_group->lock);
8146
8147 if (!block_group->ro) {
8148 spin_unlock(&block_group->lock);
8149 continue;
8150 }
8151
8152 if (block_group->flags & (BTRFS_BLOCK_GROUP_RAID1 |
8153 BTRFS_BLOCK_GROUP_RAID10 |
8154 BTRFS_BLOCK_GROUP_DUP))
8155 factor = 2;
8156 else
8157 factor = 1;
8158
8159 free_bytes += (block_group->key.offset -
8160 btrfs_block_group_used(&block_group->item)) *
8161 factor;
8162
8163 spin_unlock(&block_group->lock);
8164 }
8165
8166 return free_bytes;
8167 }
8168
8169 /*
8170 * helper to account the unused space of all the readonly block group in the
8171 * space_info. takes mirrors into account.
8172 */
8173 u64 btrfs_account_ro_block_groups_free_space(struct btrfs_space_info *sinfo)
8174 {
8175 int i;
8176 u64 free_bytes = 0;
8177
8178 spin_lock(&sinfo->lock);
8179
8180 for(i = 0; i < BTRFS_NR_RAID_TYPES; i++)
8181 if (!list_empty(&sinfo->block_groups[i]))
8182 free_bytes += __btrfs_get_ro_block_group_free_space(
8183 &sinfo->block_groups[i]);
8184
8185 spin_unlock(&sinfo->lock);
8186
8187 return free_bytes;
8188 }
8189
8190 int btrfs_set_block_group_rw(struct btrfs_root *root,
8191 struct btrfs_block_group_cache *cache)
8192 {
8193 struct btrfs_space_info *sinfo = cache->space_info;
8194 u64 num_bytes;
8195
8196 BUG_ON(!cache->ro);
8197
8198 spin_lock(&sinfo->lock);
8199 spin_lock(&cache->lock);
8200 num_bytes = cache->key.offset - cache->reserved - cache->pinned -
8201 cache->bytes_super - btrfs_block_group_used(&cache->item);
8202 sinfo->bytes_readonly -= num_bytes;
8203 cache->ro = 0;
8204 spin_unlock(&cache->lock);
8205 spin_unlock(&sinfo->lock);
8206 return 0;
8207 }
8208
8209 /*
8210 * checks to see if its even possible to relocate this block group.
8211 *
8212 * @return - -1 if it's not a good idea to relocate this block group, 0 if its
8213 * ok to go ahead and try.
8214 */
8215 int btrfs_can_relocate(struct btrfs_root *root, u64 bytenr)
8216 {
8217 struct btrfs_block_group_cache *block_group;
8218 struct btrfs_space_info *space_info;
8219 struct btrfs_fs_devices *fs_devices = root->fs_info->fs_devices;
8220 struct btrfs_device *device;
8221 int full = 0;
8222 int ret = 0;
8223
8224 block_group = btrfs_lookup_block_group(root->fs_info, bytenr);
8225
8226 /* odd, couldn't find the block group, leave it alone */
8227 if (!block_group)
8228 return -1;
8229
8230 /* no bytes used, we're good */
8231 if (!btrfs_block_group_used(&block_group->item))
8232 goto out;
8233
8234 space_info = block_group->space_info;
8235 spin_lock(&space_info->lock);
8236
8237 full = space_info->full;
8238
8239 /*
8240 * if this is the last block group we have in this space, we can't
8241 * relocate it unless we're able to allocate a new chunk below.
8242 *
8243 * Otherwise, we need to make sure we have room in the space to handle
8244 * all of the extents from this block group. If we can, we're good
8245 */
8246 if ((space_info->total_bytes != block_group->key.offset) &&
8247 (space_info->bytes_used + space_info->bytes_reserved +
8248 space_info->bytes_pinned + space_info->bytes_readonly +
8249 btrfs_block_group_used(&block_group->item) <
8250 space_info->total_bytes)) {
8251 spin_unlock(&space_info->lock);
8252 goto out;
8253 }
8254 spin_unlock(&space_info->lock);
8255
8256 /*
8257 * ok we don't have enough space, but maybe we have free space on our
8258 * devices to allocate new chunks for relocation, so loop through our
8259 * alloc devices and guess if we have enough space. However, if we
8260 * were marked as full, then we know there aren't enough chunks, and we
8261 * can just return.
8262 */
8263 ret = -1;
8264 if (full)
8265 goto out;
8266
8267 mutex_lock(&root->fs_info->chunk_mutex);
8268 list_for_each_entry(device, &fs_devices->alloc_list, dev_alloc_list) {
8269 u64 min_free = btrfs_block_group_used(&block_group->item);
8270 u64 dev_offset;
8271
8272 /*
8273 * check to make sure we can actually find a chunk with enough
8274 * space to fit our block group in.
8275 */
8276 if (device->total_bytes > device->bytes_used + min_free) {
8277 ret = find_free_dev_extent(NULL, device, min_free,
8278 &dev_offset, NULL);
8279 if (!ret)
8280 break;
8281 ret = -1;
8282 }
8283 }
8284 mutex_unlock(&root->fs_info->chunk_mutex);
8285 out:
8286 btrfs_put_block_group(block_group);
8287 return ret;
8288 }
8289
8290 static int find_first_block_group(struct btrfs_root *root,
8291 struct btrfs_path *path, struct btrfs_key *key)
8292 {
8293 int ret = 0;
8294 struct btrfs_key found_key;
8295 struct extent_buffer *leaf;
8296 int slot;
8297
8298 ret = btrfs_search_slot(NULL, root, key, path, 0, 0);
8299 if (ret < 0)
8300 goto out;
8301
8302 while (1) {
8303 slot = path->slots[0];
8304 leaf = path->nodes[0];
8305 if (slot >= btrfs_header_nritems(leaf)) {
8306 ret = btrfs_next_leaf(root, path);
8307 if (ret == 0)
8308 continue;
8309 if (ret < 0)
8310 goto out;
8311 break;
8312 }
8313 btrfs_item_key_to_cpu(leaf, &found_key, slot);
8314
8315 if (found_key.objectid >= key->objectid &&
8316 found_key.type == BTRFS_BLOCK_GROUP_ITEM_KEY) {
8317 ret = 0;
8318 goto out;
8319 }
8320 path->slots[0]++;
8321 }
8322 out:
8323 return ret;
8324 }
8325
8326 void btrfs_put_block_group_cache(struct btrfs_fs_info *info)
8327 {
8328 struct btrfs_block_group_cache *block_group;
8329 u64 last = 0;
8330
8331 while (1) {
8332 struct inode *inode;
8333
8334 block_group = btrfs_lookup_first_block_group(info, last);
8335 while (block_group) {
8336 spin_lock(&block_group->lock);
8337 if (block_group->iref)
8338 break;
8339 spin_unlock(&block_group->lock);
8340 block_group = next_block_group(info->tree_root,
8341 block_group);
8342 }
8343 if (!block_group) {
8344 if (last == 0)
8345 break;
8346 last = 0;
8347 continue;
8348 }
8349
8350 inode = block_group->inode;
8351 block_group->iref = 0;
8352 block_group->inode = NULL;
8353 spin_unlock(&block_group->lock);
8354 iput(inode);
8355 last = block_group->key.objectid + block_group->key.offset;
8356 btrfs_put_block_group(block_group);
8357 }
8358 }
8359
8360 int btrfs_free_block_groups(struct btrfs_fs_info *info)
8361 {
8362 struct btrfs_block_group_cache *block_group;
8363 struct btrfs_space_info *space_info;
8364 struct btrfs_caching_control *caching_ctl;
8365 struct rb_node *n;
8366
8367 down_write(&info->extent_commit_sem);
8368 while (!list_empty(&info->caching_block_groups)) {
8369 caching_ctl = list_entry(info->caching_block_groups.next,
8370 struct btrfs_caching_control, list);
8371 list_del(&caching_ctl->list);
8372 put_caching_control(caching_ctl);
8373 }
8374 up_write(&info->extent_commit_sem);
8375
8376 spin_lock(&info->block_group_cache_lock);
8377 while ((n = rb_last(&info->block_group_cache_tree)) != NULL) {
8378 block_group = rb_entry(n, struct btrfs_block_group_cache,
8379 cache_node);
8380 rb_erase(&block_group->cache_node,
8381 &info->block_group_cache_tree);
8382 spin_unlock(&info->block_group_cache_lock);
8383
8384 down_write(&block_group->space_info->groups_sem);
8385 list_del(&block_group->list);
8386 up_write(&block_group->space_info->groups_sem);
8387
8388 if (block_group->cached == BTRFS_CACHE_STARTED)
8389 wait_block_group_cache_done(block_group);
8390
8391 /*
8392 * We haven't cached this block group, which means we could
8393 * possibly have excluded extents on this block group.
8394 */
8395 if (block_group->cached == BTRFS_CACHE_NO)
8396 free_excluded_extents(info->extent_root, block_group);
8397
8398 btrfs_remove_free_space_cache(block_group);
8399 btrfs_put_block_group(block_group);
8400
8401 spin_lock(&info->block_group_cache_lock);
8402 }
8403 spin_unlock(&info->block_group_cache_lock);
8404
8405 /* now that all the block groups are freed, go through and
8406 * free all the space_info structs. This is only called during
8407 * the final stages of unmount, and so we know nobody is
8408 * using them. We call synchronize_rcu() once before we start,
8409 * just to be on the safe side.
8410 */
8411 synchronize_rcu();
8412
8413 release_global_block_rsv(info);
8414
8415 while(!list_empty(&info->space_info)) {
8416 space_info = list_entry(info->space_info.next,
8417 struct btrfs_space_info,
8418 list);
8419 if (space_info->bytes_pinned > 0 ||
8420 space_info->bytes_reserved > 0) {
8421 WARN_ON(1);
8422 dump_space_info(space_info, 0, 0);
8423 }
8424 list_del(&space_info->list);
8425 kfree(space_info);
8426 }
8427 return 0;
8428 }
8429
8430 static void __link_block_group(struct btrfs_space_info *space_info,
8431 struct btrfs_block_group_cache *cache)
8432 {
8433 int index = get_block_group_index(cache);
8434
8435 down_write(&space_info->groups_sem);
8436 list_add_tail(&cache->list, &space_info->block_groups[index]);
8437 up_write(&space_info->groups_sem);
8438 }
8439
8440 int btrfs_read_block_groups(struct btrfs_root *root)
8441 {
8442 struct btrfs_path *path;
8443 int ret;
8444 struct btrfs_block_group_cache *cache;
8445 struct btrfs_fs_info *info = root->fs_info;
8446 struct btrfs_space_info *space_info;
8447 struct btrfs_key key;
8448 struct btrfs_key found_key;
8449 struct extent_buffer *leaf;
8450 int need_clear = 0;
8451 u64 cache_gen;
8452
8453 root = info->extent_root;
8454 key.objectid = 0;
8455 key.offset = 0;
8456 btrfs_set_key_type(&key, BTRFS_BLOCK_GROUP_ITEM_KEY);
8457 path = btrfs_alloc_path();
8458 if (!path)
8459 return -ENOMEM;
8460
8461 cache_gen = btrfs_super_cache_generation(&root->fs_info->super_copy);
8462 if (cache_gen != 0 &&
8463 btrfs_super_generation(&root->fs_info->super_copy) != cache_gen)
8464 need_clear = 1;
8465 if (btrfs_test_opt(root, CLEAR_CACHE))
8466 need_clear = 1;
8467 if (!btrfs_test_opt(root, SPACE_CACHE) && cache_gen)
8468 printk(KERN_INFO "btrfs: disk space caching is enabled\n");
8469
8470 while (1) {
8471 ret = find_first_block_group(root, path, &key);
8472 if (ret > 0)
8473 break;
8474 if (ret != 0)
8475 goto error;
8476 leaf = path->nodes[0];
8477 btrfs_item_key_to_cpu(leaf, &found_key, path->slots[0]);
8478 cache = kzalloc(sizeof(*cache), GFP_NOFS);
8479 if (!cache) {
8480 ret = -ENOMEM;
8481 goto error;
8482 }
8483
8484 atomic_set(&cache->count, 1);
8485 spin_lock_init(&cache->lock);
8486 spin_lock_init(&cache->tree_lock);
8487 cache->fs_info = info;
8488 INIT_LIST_HEAD(&cache->list);
8489 INIT_LIST_HEAD(&cache->cluster_list);
8490
8491 if (need_clear)
8492 cache->disk_cache_state = BTRFS_DC_CLEAR;
8493
8494 /*
8495 * we only want to have 32k of ram per block group for keeping
8496 * track of free space, and if we pass 1/2 of that we want to
8497 * start converting things over to using bitmaps
8498 */
8499 cache->extents_thresh = ((1024 * 32) / 2) /
8500 sizeof(struct btrfs_free_space);
8501
8502 read_extent_buffer(leaf, &cache->item,
8503 btrfs_item_ptr_offset(leaf, path->slots[0]),
8504 sizeof(cache->item));
8505 memcpy(&cache->key, &found_key, sizeof(found_key));
8506
8507 key.objectid = found_key.objectid + found_key.offset;
8508 btrfs_release_path(root, path);
8509 cache->flags = btrfs_block_group_flags(&cache->item);
8510 cache->sectorsize = root->sectorsize;
8511
8512 /*
8513 * We need to exclude the super stripes now so that the space
8514 * info has super bytes accounted for, otherwise we'll think
8515 * we have more space than we actually do.
8516 */
8517 exclude_super_stripes(root, cache);
8518
8519 /*
8520 * check for two cases, either we are full, and therefore
8521 * don't need to bother with the caching work since we won't
8522 * find any space, or we are empty, and we can just add all
8523 * the space in and be done with it. This saves us _alot_ of
8524 * time, particularly in the full case.
8525 */
8526 if (found_key.offset == btrfs_block_group_used(&cache->item)) {
8527 cache->last_byte_to_unpin = (u64)-1;
8528 cache->cached = BTRFS_CACHE_FINISHED;
8529 free_excluded_extents(root, cache);
8530 } else if (btrfs_block_group_used(&cache->item) == 0) {
8531 cache->last_byte_to_unpin = (u64)-1;
8532 cache->cached = BTRFS_CACHE_FINISHED;
8533 add_new_free_space(cache, root->fs_info,
8534 found_key.objectid,
8535 found_key.objectid +
8536 found_key.offset);
8537 free_excluded_extents(root, cache);
8538 }
8539
8540 ret = update_space_info(info, cache->flags, found_key.offset,
8541 btrfs_block_group_used(&cache->item),
8542 &space_info);
8543 BUG_ON(ret);
8544 cache->space_info = space_info;
8545 spin_lock(&cache->space_info->lock);
8546 cache->space_info->bytes_readonly += cache->bytes_super;
8547 spin_unlock(&cache->space_info->lock);
8548
8549 __link_block_group(space_info, cache);
8550
8551 ret = btrfs_add_block_group_cache(root->fs_info, cache);
8552 BUG_ON(ret);
8553
8554 set_avail_alloc_bits(root->fs_info, cache->flags);
8555 if (btrfs_chunk_readonly(root, cache->key.objectid))
8556 set_block_group_ro(cache);
8557 }
8558
8559 list_for_each_entry_rcu(space_info, &root->fs_info->space_info, list) {
8560 if (!(get_alloc_profile(root, space_info->flags) &
8561 (BTRFS_BLOCK_GROUP_RAID10 |
8562 BTRFS_BLOCK_GROUP_RAID1 |
8563 BTRFS_BLOCK_GROUP_DUP)))
8564 continue;
8565 /*
8566 * avoid allocating from un-mirrored block group if there are
8567 * mirrored block groups.
8568 */
8569 list_for_each_entry(cache, &space_info->block_groups[3], list)
8570 set_block_group_ro(cache);
8571 list_for_each_entry(cache, &space_info->block_groups[4], list)
8572 set_block_group_ro(cache);
8573 }
8574
8575 init_global_block_rsv(info);
8576 ret = 0;
8577 error:
8578 btrfs_free_path(path);
8579 return ret;
8580 }
8581
8582 int btrfs_make_block_group(struct btrfs_trans_handle *trans,
8583 struct btrfs_root *root, u64 bytes_used,
8584 u64 type, u64 chunk_objectid, u64 chunk_offset,
8585 u64 size)
8586 {
8587 int ret;
8588 struct btrfs_root *extent_root;
8589 struct btrfs_block_group_cache *cache;
8590
8591 extent_root = root->fs_info->extent_root;
8592
8593 root->fs_info->last_trans_log_full_commit = trans->transid;
8594
8595 cache = kzalloc(sizeof(*cache), GFP_NOFS);
8596 if (!cache)
8597 return -ENOMEM;
8598
8599 cache->key.objectid = chunk_offset;
8600 cache->key.offset = size;
8601 cache->key.type = BTRFS_BLOCK_GROUP_ITEM_KEY;
8602 cache->sectorsize = root->sectorsize;
8603 cache->fs_info = root->fs_info;
8604
8605 /*
8606 * we only want to have 32k of ram per block group for keeping track
8607 * of free space, and if we pass 1/2 of that we want to start
8608 * converting things over to using bitmaps
8609 */
8610 cache->extents_thresh = ((1024 * 32) / 2) /
8611 sizeof(struct btrfs_free_space);
8612 atomic_set(&cache->count, 1);
8613 spin_lock_init(&cache->lock);
8614 spin_lock_init(&cache->tree_lock);
8615 INIT_LIST_HEAD(&cache->list);
8616 INIT_LIST_HEAD(&cache->cluster_list);
8617
8618 btrfs_set_block_group_used(&cache->item, bytes_used);
8619 btrfs_set_block_group_chunk_objectid(&cache->item, chunk_objectid);
8620 cache->flags = type;
8621 btrfs_set_block_group_flags(&cache->item, type);
8622
8623 cache->last_byte_to_unpin = (u64)-1;
8624 cache->cached = BTRFS_CACHE_FINISHED;
8625 exclude_super_stripes(root, cache);
8626
8627 add_new_free_space(cache, root->fs_info, chunk_offset,
8628 chunk_offset + size);
8629
8630 free_excluded_extents(root, cache);
8631
8632 ret = update_space_info(root->fs_info, cache->flags, size, bytes_used,
8633 &cache->space_info);
8634 BUG_ON(ret);
8635
8636 spin_lock(&cache->space_info->lock);
8637 cache->space_info->bytes_readonly += cache->bytes_super;
8638 spin_unlock(&cache->space_info->lock);
8639
8640 __link_block_group(cache->space_info, cache);
8641
8642 ret = btrfs_add_block_group_cache(root->fs_info, cache);
8643 BUG_ON(ret);
8644
8645 ret = btrfs_insert_item(trans, extent_root, &cache->key, &cache->item,
8646 sizeof(cache->item));
8647 BUG_ON(ret);
8648
8649 set_avail_alloc_bits(extent_root->fs_info, type);
8650
8651 return 0;
8652 }
8653
8654 int btrfs_remove_block_group(struct btrfs_trans_handle *trans,
8655 struct btrfs_root *root, u64 group_start)
8656 {
8657 struct btrfs_path *path;
8658 struct btrfs_block_group_cache *block_group;
8659 struct btrfs_free_cluster *cluster;
8660 struct btrfs_root *tree_root = root->fs_info->tree_root;
8661 struct btrfs_key key;
8662 struct inode *inode;
8663 int ret;
8664 int factor;
8665
8666 root = root->fs_info->extent_root;
8667
8668 block_group = btrfs_lookup_block_group(root->fs_info, group_start);
8669 BUG_ON(!block_group);
8670 BUG_ON(!block_group->ro);
8671
8672 /*
8673 * Free the reserved super bytes from this block group before
8674 * remove it.
8675 */
8676 free_excluded_extents(root, block_group);
8677
8678 memcpy(&key, &block_group->key, sizeof(key));
8679 if (block_group->flags & (BTRFS_BLOCK_GROUP_DUP |
8680 BTRFS_BLOCK_GROUP_RAID1 |
8681 BTRFS_BLOCK_GROUP_RAID10))
8682 factor = 2;
8683 else
8684 factor = 1;
8685
8686 /* make sure this block group isn't part of an allocation cluster */
8687 cluster = &root->fs_info->data_alloc_cluster;
8688 spin_lock(&cluster->refill_lock);
8689 btrfs_return_cluster_to_free_space(block_group, cluster);
8690 spin_unlock(&cluster->refill_lock);
8691
8692 /*
8693 * make sure this block group isn't part of a metadata
8694 * allocation cluster
8695 */
8696 cluster = &root->fs_info->meta_alloc_cluster;
8697 spin_lock(&cluster->refill_lock);
8698 btrfs_return_cluster_to_free_space(block_group, cluster);
8699 spin_unlock(&cluster->refill_lock);
8700
8701 path = btrfs_alloc_path();
8702 BUG_ON(!path);
8703
8704 inode = lookup_free_space_inode(root, block_group, path);
8705 if (!IS_ERR(inode)) {
8706 btrfs_orphan_add(trans, inode);
8707 clear_nlink(inode);
8708 /* One for the block groups ref */
8709 spin_lock(&block_group->lock);
8710 if (block_group->iref) {
8711 block_group->iref = 0;
8712 block_group->inode = NULL;
8713 spin_unlock(&block_group->lock);
8714 iput(inode);
8715 } else {
8716 spin_unlock(&block_group->lock);
8717 }
8718 /* One for our lookup ref */
8719 iput(inode);
8720 }
8721
8722 key.objectid = BTRFS_FREE_SPACE_OBJECTID;
8723 key.offset = block_group->key.objectid;
8724 key.type = 0;
8725
8726 ret = btrfs_search_slot(trans, tree_root, &key, path, -1, 1);
8727 if (ret < 0)
8728 goto out;
8729 if (ret > 0)
8730 btrfs_release_path(tree_root, path);
8731 if (ret == 0) {
8732 ret = btrfs_del_item(trans, tree_root, path);
8733 if (ret)
8734 goto out;
8735 btrfs_release_path(tree_root, path);
8736 }
8737
8738 spin_lock(&root->fs_info->block_group_cache_lock);
8739 rb_erase(&block_group->cache_node,
8740 &root->fs_info->block_group_cache_tree);
8741 spin_unlock(&root->fs_info->block_group_cache_lock);
8742
8743 down_write(&block_group->space_info->groups_sem);
8744 /*
8745 * we must use list_del_init so people can check to see if they
8746 * are still on the list after taking the semaphore
8747 */
8748 list_del_init(&block_group->list);
8749 up_write(&block_group->space_info->groups_sem);
8750
8751 if (block_group->cached == BTRFS_CACHE_STARTED)
8752 wait_block_group_cache_done(block_group);
8753
8754 btrfs_remove_free_space_cache(block_group);
8755
8756 spin_lock(&block_group->space_info->lock);
8757 block_group->space_info->total_bytes -= block_group->key.offset;
8758 block_group->space_info->bytes_readonly -= block_group->key.offset;
8759 block_group->space_info->disk_total -= block_group->key.offset * factor;
8760 spin_unlock(&block_group->space_info->lock);
8761
8762 memcpy(&key, &block_group->key, sizeof(key));
8763
8764 btrfs_clear_space_info_full(root->fs_info);
8765
8766 btrfs_put_block_group(block_group);
8767 btrfs_put_block_group(block_group);
8768
8769 ret = btrfs_search_slot(trans, root, &key, path, -1, 1);
8770 if (ret > 0)
8771 ret = -EIO;
8772 if (ret < 0)
8773 goto out;
8774
8775 ret = btrfs_del_item(trans, root, path);
8776 out:
8777 btrfs_free_path(path);
8778 return ret;
8779 }
8780
8781 int btrfs_init_space_info(struct btrfs_fs_info *fs_info)
8782 {
8783 struct btrfs_space_info *space_info;
8784 int ret;
8785
8786 ret = update_space_info(fs_info, BTRFS_BLOCK_GROUP_SYSTEM, 0, 0,
8787 &space_info);
8788 if (ret)
8789 return ret;
8790
8791 ret = update_space_info(fs_info, BTRFS_BLOCK_GROUP_METADATA, 0, 0,
8792 &space_info);
8793 if (ret)
8794 return ret;
8795
8796 ret = update_space_info(fs_info, BTRFS_BLOCK_GROUP_DATA, 0, 0,
8797 &space_info);
8798 if (ret)
8799 return ret;
8800
8801 return ret;
8802 }
8803
8804 int btrfs_error_unpin_extent_range(struct btrfs_root *root, u64 start, u64 end)
8805 {
8806 return unpin_extent_range(root, start, end);
8807 }
8808
8809 int btrfs_error_discard_extent(struct btrfs_root *root, u64 bytenr,
8810 u64 num_bytes, u64 *actual_bytes)
8811 {
8812 return btrfs_discard_extent(root, bytenr, num_bytes, actual_bytes);
8813 }
8814
8815 int btrfs_trim_fs(struct btrfs_root *root, struct fstrim_range *range)
8816 {
8817 struct btrfs_fs_info *fs_info = root->fs_info;
8818 struct btrfs_block_group_cache *cache = NULL;
8819 u64 group_trimmed;
8820 u64 start;
8821 u64 end;
8822 u64 trimmed = 0;
8823 int ret = 0;
8824
8825 cache = btrfs_lookup_block_group(fs_info, range->start);
8826
8827 while (cache) {
8828 if (cache->key.objectid >= (range->start + range->len)) {
8829 btrfs_put_block_group(cache);
8830 break;
8831 }
8832
8833 start = max(range->start, cache->key.objectid);
8834 end = min(range->start + range->len,
8835 cache->key.objectid + cache->key.offset);
8836
8837 if (end - start >= range->minlen) {
8838 if (!block_group_cache_done(cache)) {
8839 ret = cache_block_group(cache, NULL, root, 0);
8840 if (!ret)
8841 wait_block_group_cache_done(cache);
8842 }
8843 ret = btrfs_trim_block_group(cache,
8844 &group_trimmed,
8845 start,
8846 end,
8847 range->minlen);
8848
8849 trimmed += group_trimmed;
8850 if (ret) {
8851 btrfs_put_block_group(cache);
8852 break;
8853 }
8854 }
8855
8856 cache = next_block_group(fs_info->tree_root, cache);
8857 }
8858
8859 range->len = trimmed;
8860 return ret;
8861 }
Linux 2.6 ibm-acpi/thinkpad-acpi driver git tree